Agate is an incredibly striking gemstone due to its enticing coloring and unique structure. However, there isn’t just one type of agate. There are multiple versions of the stone, each with its own unique characteristics. Here’s a closer look at the agate gemstone, including an overview of 11 different types of agate and some commonly asked questions.

What Are Agates?

Agates are a type of chalcedony, which is a mineral group that includes gemstones like aventurine, bloodstone, carnelian, chrysoprase, jasper, and onyx. Chalcedony is technically a type of quartz.

What makes agate unique is that it’s a banded chalcedony. As a result, there are highly-defined segments that can have varying levels of color and transparency.

Is Agate a Rock or a Mineral?

Technically, agate is a silica mineraloid. It’s naturally occurring and doesn’t exhibit crystallinity, but it doesn’t have the exact structure of a traditional mineral.

How Do I Identify an Agate Stone?

Usually, the easiest way to identify agate is to look for specific characteristics and its composition. Agate gems contain chalcedony minerals and exhibit clear layers. Generally, the stone is translucent, though some bands may appear opaquer or more transparent than others.

How Is an Agate formed?

The agate semi precious gemstone that forms when silica-rich water fills rock voids, particularly volcanic rock voids. As the water leaves, silica mineral deposits remain, and they functionally form gemstone crystals. Over time, numerous layers develop, leading to an agate.

History of the Mineral Agate

It’s believed that agate was discovered as far back as the 3rd or 4th century BCE. The name is derived from the Achates River in Sicily, Italy, where the gemstone was first discovered in an official sense.

Agate was used as an ornamental stone in Ancient Greece, often featured in seal stones and jewelry. Beads were a popular option, with evidence showing they were used by those living in the Indus Valley civilization.

Where Are Agates Found?

Agate is an incredibly common gemstone, and it’s found all over the world. It’s present in multiple US states, particularly those associated with volcanic activities. Brazil, Germany, and Uruguay are also known as sources of agate. However, other nations also have surprising quantities of agate, including Austria, Canada, Chile, Iraq, Morocco, New Zealand, Portugal, Russia, South Africa, Thailand, and more.

Metaphysical Properties of Agate

The metaphysical properties of agate aren’t exactly set, as some may vary depending on a person’s belief system and the exact type of agate involved. However, many consider agate a grounding stone. It’s said to be soothing or calming and helps balance positive and negative energies.

Many also feel that agate is a stone of self-reflection and perception, allowing a person to improve their well-being and identify challenges or obstacles that are holding them back, creating opportunities for correction. Some also think it helps keep a person’s expectations realistic, particularly during times of change.

Some believe that agate also possesses healing properties, particularly when it comes to the lymphatic and circulatory systems. However, there’s no scientific proof that agate or any other stone can prevent or treat any medical condition. As a result, agate isn’t a substitute for genuine medical care.

Types of Agate: What Are the Different Types of Agate?

Blue Lace Agate

Largely originating from Kenya and Namibia, blue lace agate features soft blue to lilac coloring with white banding. The banding is usually wavy, and the edges may be slightly speckled, creating the look of lace.

Botswana Agate

Botswana agate is a clearly banded type of agate that exhibits an area of colors, particularly gray and pink. The stones originate specifically from Botswana, which is in the southern part of Africa.

Crazy Lace Agate

Crazy lace agate features distinctive colors and an array of complex patterns due to various inclusions. While there are distinct bands, they aren’t necessarily linear. As a result, there are often swirled sections and ample amounts of curves.

Dendritic Agate (Plentitude Stone)

Dendric agate contains dendrites, which are fern-like structures created by various mineral inclusions. The patterning is often incredibly bold, and no two pieces feature the same imagery, ensuring every cut sample is inherently unique.

Fire Agate

Fire agate is one of the more opaque versions of agate, often coming in rich, fiery hues like yellow, orange, and red. It has an iridescent quality that creates the appearance of metallic-like shades, causing the stone to glow coppery, brassy, or golden.

Fortification Agate or Banded Agate

Fortification agate – also referred to as banded agate – has clear lines that are typically curved bands incredibly close to parallel. Often, the look of fortification agate is what comes to people’s minds when they envision the stone.

Iris Agate

Iris agate has the banded look you expect with agate, but it also has a unique feature. Some segments – or the entire specimen – have an optical quality that creates an iridescent effect, leading to a rainbow of colors when viewed from different angles.

Lake Superior Agate

Lake Superior agate is found near Lake Superior in North America. Often, the stones feature distinct layers, but they often form as irregular spheres. The coloring can vary, though there are typically sections with a reddish hue due to the presence of iron.

Moss Agate and Plume Agate

Moss agate is a green and white version of the stone that has green inclusions, that create an organic shape, not unlike moss. Plume agate is similar to green moss agate, due to its inclusions. It typically exhibits patterns that resemble cloud formations or smoke, and some can look like feathers.

Picture Agate or Scenic Agate

Picture agate is an agate gemstone with inclusions that create images that resemble nature scenes. Also referred to as scenic agate, this version of the gem is often one of the most popular due to its unique look.

Turritella Agate

Turritella agate contains silicified shells, leading to unique patterns within the stone. Typically, these stones are found in Wyoming and feature earthy hues with translucent to semi-transparent sections.

Common Questions about Agate Stones

What Is Grape Agate?

Grape agate isn’t technically an agate, as it lacks the characteristic banding found in agate. Instead, it’s a market name for a purple stone that features spherical quartz crystal formation, generally with a druzy-like surface. The name is due to the stone’s coloring and the fact that the spheres can resemble a bunch of grapes.

What Is the Rarest Agate Color?

Generally, the rarest of agate types by color is purple. However, dendritic agate – which is also called the plentitude stone – is often the most valuable. Iris agate is also highly prized due to its striking coloring. Ellensburg Blue agates are another incredibly rare version, featuring a gentle purplish-blue hue that can have a pinkish tint under certain lighting.

Another rare variety is polyhedroid agate. With this, the agate forms in distinct geometric shapes. Often, there are straight lines that create quadrilaterals or triangles, typically due to the straight edges of the rocks surrounding the void where it forms.

What Is the Most Common Agate?

Overall, fortification agate is the most common version. That’s particularly true when the stone contains primarily classic colors associated with agate, including white, red, brown, gray, and yellow.

Are Blue Agate and Blue Lace Agate the Same Thing?

Blue agate and blue lace agate aren’t necessarily the same thing. The main difference is the patterning. Blue lace agate has edges on the bands that create a lace-like pattern. With blue agate, other designs may exist, including more traditional bands with distinctly smooth edges.

However, both can have highly similar coloring and composition. As a result, small pieces of both stones without much banding may look identical.

Is Carnelian Agate?

Carnelian in and of itself isn’t agate. Instead, it’s a red, orange, or amber-colored chalcedony mineral. However, some agates feature carnelian. As a result, a carnelian with banding is technically a version of agate. But if the banding isn’t present, carnelian isn’t jointly classified as an agate.

Is Onyx Agate?

As with carnelian, onyx isn’t necessarily a type of agate on its own. However, if it features banding, it’s potentially considered an onyx agate. In that case, the bands – which may feature different hues of onyx or other kinds of chalcedony – are what make it an agate. If the colored bands themselves aren’t present, the piece is only classified as onyx.

How Do I Tell If an Agate Is Real?

Genuine agate features clear layers and banding. If the layers aren’t distinct, then there’s a decent chance that the stone isn’t agate. Additionally, agate won’t contain bubbles, so bubbles within the gem are a red flag.

Agate also doesn’t come in especially bright colors. However, some people dye agate to achieve incredibly vibrant hues. In that case, the overly strong coloration isn’t necessarily a sign that the stone itself isn’t authentic, just that it was treated to create hues that don’t occur in nature. Similarly, overly even coloring within the bands typically indicates the agate stone being dyed, as natural agate usually has some slight variations, even within individual bands.

Another sign of a fake is if the surface is easy to scratch. Agate has a Mohs hardness rating of 7, so it’s pretty tough. If there are scratches on the surface not caused by cutting tools, that’s usually a sign of a fake.

Agate is also a dense stone. As a result, it feels heavy for its size in most cases. If an agate gemstone seems light in hand, it’s unlikely that it’s a genuine agate stone.

Finally, if the entire piece of agate is opaque, that usually means it’s not genuine. While the degree of transparency can vary, agate is generally closer to translucent. As a result, light does pass through the stone, albeit a bit impeded. If no light penetrates through any band, it’s likely a fake.

Agate Types & Geological Properties of the Agate Crystal

The agate crystal is a microcrystalline-quartz mineraloid that has a lustrous display of multi-color banding and results from long-term accumulations of siliceous groundwater deposits in rock cavities. Much like other mineraloids, all agate types form over thousands of years inside the existing voids of other igneous, sedimentary, and metamorphic rocks that contain silica-rich groundwater. And color formations and patterns can vary depending on numerous environmental factors. In fact, the layering and banding typically visible within an agate gemstone is representative of the shapes of the voids from which it develops. Agate is a popular and highly marketable stone amongst gem enthusiasts worldwide. This is mostly due to its colorful displays, mystifying geological origins, and its spiritual and cultural affiliations. Updated September 10, 2022.

How to Pronounce Agate

Despite the simple spelling of this gemstone, many inquire about its proper pronunciation. Professional geologists at institutions around the world pronounce agate crystal (in the American-English language) as “ae-get.” To demonstrate, the short video below provides a voice-recording of the formal pronunciation.

How the Agate Crystal Got its Name

The name “Agate” relates to the Greek name of the Dirillo River in Sicily, which was “Achates” or “Acate.” In fact, historians believe this is where the semiprecious stone was first discovered by the early earth scientist and Greek Philosopher named Theophrastus. Its initial discovery took place around 371 to 287 BCE. And since then, various cultures value this gemstone for its neat appearance and spiritual affiliations.

Physical Properties of the Agate Crystal

Although this siliceous gemstone isn’t a mineral, geologists still perform the appropriate laboratory tests to report its physical properties, in the same fashion. The following mineral physical properties apply to this mineraloid:

• Color: Variable
• Streak: White
• Luster: Waxy-Flat
• Cleavage: None
• Mohs Hardness Scale: 6.5 to 7.0
• Specific Gravity: 2.6 grams per cubic centimeter (g/cm3)
• Chemical Composition: Variety of microcrystalline form quartz (SiO2)
• Crystal Structure: Amorphous (none)

Various Colors in Agate Types

An agate gemstone can develop to display a variety of common colors. These stones can have numerous shades of one color, or a combination of entirely different colors. For example, in the photograph below, the specimen on the left displays multiple shades of different colors. Whereas the specimen on the right displays various shades of the same color. These color variations are the result of alternating silica composition, pH, and other chemical properties in groundwater at the time of crystallization. In fact, each display of color is the result of different-sized silica spheres. And the color one sees is the material-specific light-reflection property.

Geology of Agate

An agate crystal forms within the cavities of other rocks in acidic to neutral environments. Its formation occurs by the accumulation of silica-rich groundwater in rock voids, over thousands of years. In fact, these chalcedony veins mostly develop within the voids of volcanic igneous rocks and plutonic igneous rocks. This is because igneous rocks have a higher tendency to hold groundwater over long periods of time. As a result, the semiprecious stone forms banding layers over time, that are generally parallel to the surrounding cavity walls.

Although it is possible, this mineraloid is less likely to form within metamorphic rocks and sedimentary rocks due to the lower chance of water retention. To illustrate, such rocks have higher porosity, permeability, and transmissivity properties, and result in groundwater moving through them rather than accumulating within them.

Geological Rock Classification

The agate gemstone is not a sedimentary rock, nor is it metamorphic or igneous. In fact, it isn’t categorizable as any one of the three geologic rock types. Some gem enthusiasts also debate whether it’s a mineral or not. However, in the scientific field of mineralogy, it is generally understood not to be a mineral either, but rather a mineraloid due to its amorphous physical properties and geochemical composition.

Agate is a Type of Chalcedony

The agate gemstone is a type of chalcedony (with translucent physical properties), which is a general name for a microcrystalline quartz and moganite mineraloid. In terms of chemical composition, chalcedony comprises quartz and moganite, which both maintain a silicon dioxide chemical formula, however differ in crystal structure.

What are Silicates

Silicates are compounds with crystal structures that contain SiO4 tetrahedra. Silicates are either isolated or joined to form groups, rings, single or double chains, sheets, or three-dimensional frameworks.

Geodes vs Agate Crystal

Unlike a geode, which similarly forms a series of protruding quartz crystals along cavity walls, the agate types actually develop chalcedony that fully occupies the void space. In some cases, it can crystalize with or within a geode.

Agate Types

All agate types naturally form different patterns and colors on the basis of the environmental factors at the time of crystallization. For example, the most significant factors are rock geochemistry, groundwater content, and pH levels. Additionally, timeframes for crystallization and geologic activity along the way also play a role. Variations in these factors, as well as other environmental components, can shift the formation towards different colors and banding patterns or thicknesses. Thus, producing different agate typesdifferent agate types.

Firstly, rock geochemistry refers to the mineralogy of the actual rock formation that has the cavities and voids in which the chalcedony develops. As imaginable, the water content and solution changes on the basis of long-term direct contact with a particular rock.

Secondly, the chemical composition of the groundwater itself plays a strong role in the formation of chalcedony. The water-chemistry of the liquid prior to reaching the stagnant and stationary location of the void in a rock, can make the liquid-phase solution further unique. The baseline groundwater chemistry relates to the previous soils that groundwater may have migrated through, as well as the rainwater chemistry prior to percolation.

And lastly, the pH levels of the surrounding soil and groundwater during the long-term process of formation changes the solubility properties of the liquid. And this is the result of numerous environmental factors, including but not limiting to biological influences, depositional climate, metamorphism of surrounding rocks, and more. Thus, an altering pattern of amorphous microcrystalline quartz and moganite forms overtime.

1. Lace Agate Crystal

Lace agate types demonstrate bands, swirls, and concentric circles that make up intricate patterns resembling lace. These types can also comprise a wide variety of color combinations. For instance, the image below is of a blue lace stone.

2. Turritella

This stone gets its name from the voids and cavities of the fossil that it develops within. Turritella snail shells resemble a small unicorn-horn-shape. And when this salacious mineraloid occupies the void spaces, it preserves the Turritells snail fossil.

3. Carnelian Agate Gemstone

One can identify Carnelian agate crystal by its warm hues of red and orange coloration. The banding is less prominent in this type of chalcedony, but it also appears to be more consistent. Moreover, the Carnelian stones appear to be somewhat more-translucent by comparison to the other stone types. However, some gemologists indicate variable translucency factors throughout specimens.

4. Coldwater

The Coldwater stone name comes from its distinct lack of vibrant coloration. The dominant colors of this stone are cloud-white to faint blue. Additionally, there are mute-grey hues that typically swirl throughout this varietal.

5. Greek Achate

In reference to the original discovery of this semiprecious mineraloid, this title relates to the Greek name of the Dirillo River in Sicily, Italy. Colorations range from light to dark grey, red, tan, and blue, with concentric lines trending toward the center.  which can be hollow or closed.

6. Fire Agate Types

Fire agate displays an iridescent coloration resembling mother-of-pearl. In fact, the two share similar properties. Nonetheless, it maintains a combination of bright green, red, yellow, and blue-accenting across a dark background. This can give the fire agate types an appearance much like that of black opal and fire opal. As a result, it tends to be a popular choice amongst collectors.

7. Brazilian

This Brazilian semiprecious stone mostly comes from southern Brazil. This stone is famous for its large size, as well as its circular and geodetic pattern. Naturally, it comprises a variety of colors, such as grey, white, blue, and reddish-brown. However, many street vendors artificially dye and polish them to appear bright pink, light blue, and purple.

8. Polyhedroid

Polyhedroid agate is a rare formation that exists in distinct geometric shapes with straight lines forming triangles and quadrilaterals. However, these shapes are not representative of the “cleavage” property of a crystal, because it is an amorphous mineraloid as opposed to a mineral. Instead, the geometric shapes simply represent the straight lines of the void-walls from which the siliceous groundwater solidifies overtime.

9. Botswana Agate Gemstone

Botswana agate displays grey, mauve, eggplant, and Prussian-blue tones. And this characteristic banding appears to exist throughout most Botswana agate types, worldwide.

10. Plume

The plume stones exhibit a wide range of colors including blue, green, red, and purple, as well as some neutral tones. Nonetheless, an entire pallet of colors can exist in just one specimen. However, this varietal does not display banding, but rather a “plume” pattern. This appears to be similar to a thick smoke billowing from a source point.

11. Condor

Similar to the Plume stone, Condor type stones may showcase the entire spectrum of coloration in one stone. However, unlike the Plumes, this agate does display banding in a concentric fashion. With condors, each band often comprises a different color, to the effect of a brilliant rainbow display.

12. Holley Blue

The Holley Blue Stone gets its name for the pastel tones of blue and purple. It may also contain variations of dark and light bands of color that swirl throughout each specimen.

13. Moss Agate Crystal

The moss agate types get their name from the forest-green and blue-green hues. As the name suggests, the patterns have dark green coloration. It resembles moss growing on a rock.

14. Tube

The tube style stone comprises small and thin columns or “tubes” that form as the mineraloid develops. These formations result in tube-like shapes within the body of the post-crystalization agate. And when the sample is cut into slices, it typically appears with a pattern of cross-sectional circles across the stone.

15. Fortification

Fortification agate refers to the classic banded stone that forms inward from the cavity walls. However, this type may have a hollow center with protruding quartz crystals. The colors can vary, and the name comes from the clearly defined bands resembling layers of walls, or “fortification.”

16. Lake Superior Agate Gemstone

The Lake Superior agate gemstone is distinguishable by its range of red, blue, and white coloration. In fact, Lake Superior agate can range from pale to dark tones. And one common characteristic amongst this type of chalcedony stone is the banding of concentric and swirling patterns.

17. Binghamite

Binghamite is a rare variety of the chalcedony stone that forms in iron ore. The resulting coloration displays red, orange, and gold. Furthermore, most Binghamite has a distinct chatoyant, or reflective property. This is a characteristic most-visible upon polishing the stone.

18. Patuxent River

Patuxent River agate displays warm hues such as pale yellow and peach, as well as deep orange and red. There are usually no bands present, and the colors generally blend smoothly. Additionally, this stone is somewhat translucent, allowing enough light to pass through to give the stone a warm glowing appearance.

19. Enhydro Agate Crystal

Enhydro agate is essentially a mineraloid that is incomplete in the crystallization process. It usually demonstrates a dull bluish-grey color, although all color spectrums are possible depending on the environmental factors. But what makes the enhydro agate types unique is the fact that it contains groundwater inside. In fact, with expert-level cutting and polishing, an enhdryo stone can demonstrate an array of agate coloration and banding, with splashing water inside upon shaking.

Agate Spiritual Meaning & Culture

Like most gemstones, there are cultural and spiritual values with agate crystals, worldwide. Many cultures believe agate has spiritual cleansing power. For instance, agate assists in removing negative energy from one’s life and promotes the harmonious balancing of the mind, body, and spirit. Moreover, it is believed the gem helps clear a person’s mind, giving them the ability to focus on positive goals and tasks. Cultural beliefs also suggest the agate gemstone provides a calming element to a person’s life, allowing them to overcome anger, insecurities, and tension.

What Are Agates?

Agates are a type of chalcedony, which is a mineral group that includes gemstones like aventurine, bloodstone, carnelian, chrysoprase, jasper, and onyx. Chalcedony is technically a type of quartz.

What makes agate unique is that it’s a banded chalcedony. As a result, there are highly-defined segments that can have varying levels of color and transparency.

Is Agate a Rock or a Mineral?

Technically, agate is a silica mineraloid. It’s naturally occurring and doesn’t exhibit crystallinity, but it doesn’t have the exact structure of a traditional mineral.

How Do I Identify an Agate Stone?

Usually, the easiest way to identify agate is to look for specific characteristics and its composition. Agate gems contain chalcedony minerals and exhibit clear layers. Generally, the stone is translucent, though some bands may appear opaquer or more transparent than others.

How Is an Agate formed?

The agate semi precious gemstone that forms when silica-rich water fills rock voids, particularly volcanic rock voids. As the water leaves, silica mineral deposits remain, and they functionally form gemstone crystals. Over time, numerous layers develop, leading to an agate.

History of the Mineral Agate

It’s believed that agate was discovered as far back as the 3rd or 4th century BCE. The name is derived from the Achates River in Sicily, Italy, where the gemstone was first discovered in an official sense.

Agate was used as an ornamental stone in Ancient Greece, often featured in seal stones and jewelry. Beads were a popular option, with evidence showing they were used by those living in the Indus Valley civilization.

Where Are Agates Found?

Agate is an incredibly common gemstone, and it’s found all over the world. It’s present in multiple US states, particularly those associated with volcanic activities. Brazil, Germany, and Uruguay are also known as sources of agate. However, other nations also have surprising quantities of agate, including Austria, Canada, Chile, Iraq, Morocco, New Zealand, Portugal, Russia, South Africa, Thailand, and more.

Metaphysical Properties of Agate

The metaphysical properties of agate aren’t exactly set, as some may vary depending on a person’s belief system and the exact type of agate involved. However, many consider agate a grounding stone. It’s said to be soothing or calming and helps balance positive and negative energies.

Many also feel that agate is a stone of self-reflection and perception, allowing a person to improve their well-being and identify challenges or obstacles that are holding them back, creating opportunities for correction. Some also think it helps keep a person’s expectations realistic, particularly during times of change.

Some believe that agate also possesses healing properties, particularly when it comes to the lymphatic and circulatory systems. However, there’s no scientific proof that agate or any other stone can prevent or treat any medical condition. As a result, agate isn’t a substitute for genuine medical care.

Types of Agate: What Are the Different Types of Agate?

Blue Lace Agate

Largely originating from Kenya and Namibia, blue lace agate features soft blue to lilac coloring with white banding. The banding is usually wavy, and the edges may be slightly speckled, creating the look of lace.

Botswana Agate

Botswana agate is a clearly banded type of agate that exhibits an area of colors, particularly gray and pink. The stones originate specifically from Botswana, which is in the southern part of Africa.

Crazy Lace Agate

Crazy lace agate features distinctive colors and an array of complex patterns due to various inclusions. While there are distinct bands, they aren’t necessarily linear. As a result, there are often swirled sections and ample amounts of curves.

Dendritic Agate (Plentitude Stone)

Dendric agate contains dendrites, which are fern-like structures created by various mineral inclusions. The patterning is often incredibly bold, and no two pieces feature the same imagery, ensuring every cut sample is inherently unique.

Fire Agate

Fire agate is one of the more opaque versions of agate, often coming in rich, fiery hues like yellow, orange, and red. It has an iridescent quality that creates the appearance of metallic-like shades, causing the stone to glow coppery, brassy, or golden.

Fortification Agate or Banded Agate

Fortification agate – also referred to as banded agate – has clear lines that are typically curved bands incredibly close to parallel. Often, the look of fortification agate is what comes to people’s minds when they envision the stone.

Iris Agate

Iris agate has the banded look you expect with agate, but it also has a unique feature. Some segments – or the entire specimen – have an optical quality that creates an iridescent effect, leading to a rainbow of colors when viewed from different angles.

Lake Superior Agate

Lake Superior agate is found near Lake Superior in North America. Often, the stones feature distinct layers, but they often form as irregular spheres. The coloring can vary, though there are typically sections with a reddish hue due to the presence of iron.

Moss Agate and Plume Agate

Moss agate is a green and white version of the stone that has green inclusions, that create an organic shape, not unlike moss. Plume agate is similar to green moss agate, due to its inclusions. It typically exhibits patterns that resemble cloud formations or smoke, and some can look like feathers.

Picture Agate or Scenic Agate

Picture agate is an agate gemstone with inclusions that create images that resemble nature scenes. Also referred to as scenic agate, this version of the gem is often one of the most popular due to its unique look.

Turritella Agate

Turritella agate contains silicified shells, leading to unique patterns within the stone. Typically, these stones are found in Wyoming and feature earthy hues with translucent to semi-transparent sections.

Common Questions about Agate Stones

What Is Grape Agate?

Grape agate isn’t technically an agate, as it lacks the characteristic banding found in agate. Instead, it’s a market name for a purple stone that features spherical quartz crystal formation, generally with a druzy-like surface. The name is due to the stone’s coloring and the fact that the spheres can resemble a bunch of grapes.

What Is the Rarest Agate Color?

Generally, the rarest of agate types by color is purple. However, dendritic agate – which is also called the plentitude stone – is often the most valuable. Iris agate is also highly prized due to its striking coloring. Ellensburg Blue agates are another incredibly rare version, featuring a gentle purplish-blue hue that can have a pinkish tint under certain lighting.

Another rare variety is polyhedroid agate. With this, the agate forms in distinct geometric shapes. Often, there are straight lines that create quadrilaterals or triangles, typically due to the straight edges of the rocks surrounding the void where it forms.

What Is the Most Common Agate?

Overall, fortification agate is the most common version. That’s particularly true when the stone contains primarily classic colors associated with agate, including white, red, brown, gray, and yellow.

Are Blue Agate and Blue Lace Agate the Same Thing?

Blue agate and blue lace agate aren’t necessarily the same thing. The main difference is the patterning. Blue lace agate has edges on the bands that create a lace-like pattern. With blue agate, other designs may exist, including more traditional bands with distinctly smooth edges.

For more jewelries in chinainformation, please contact us. We will provide professional answers.

However, both can have highly similar coloring and composition. As a result, small pieces of both stones without much banding may look identical.

Is Carnelian Agate?

Carnelian in and of itself isn’t agate. Instead, it’s a red, orange, or amber-colored chalcedony mineral. However, some agates feature carnelian. As a result, a carnelian with banding is technically a version of agate. But if the banding isn’t present, carnelian isn’t jointly classified as an agate.

Is Onyx Agate?

As with carnelian, onyx isn’t necessarily a type of agate on its own. However, if it features banding, it’s potentially considered an onyx agate. In that case, the bands – which may feature different hues of onyx or other kinds of chalcedony – are what make it an agate. If the colored bands themselves aren’t present, the piece is only classified as onyx.

How Do I Tell If an Agate Is Real?

Genuine agate features clear layers and banding. If the layers aren’t distinct, then there’s a decent chance that the stone isn’t agate. Additionally, agate won’t contain bubbles, so bubbles within the gem are a red flag.

Agate also doesn’t come in especially bright colors. However, some people dye agate to achieve incredibly vibrant hues. In that case, the overly strong coloration isn’t necessarily a sign that the stone itself isn’t authentic, just that it was treated to create hues that don’t occur in nature. Similarly, overly even coloring within the bands typically indicates the agate stone being dyed, as natural agate usually has some slight variations, even within individual bands.

Another sign of a fake is if the surface is easy to scratch. Agate has a Mohs hardness rating of 7, so it’s pretty tough. If there are scratches on the surface not caused by cutting tools, that’s usually a sign of a fake.

Agate is also a dense stone. As a result, it feels heavy for its size in most cases. If an agate gemstone seems light in hand, it’s unlikely that it’s a genuine agate stone.

Finally, if the entire piece of agate is opaque, that usually means it’s not genuine. While the degree of transparency can vary, agate is generally closer to translucent. As a result, light does pass through the stone, albeit a bit impeded. If no light penetrates through any band, it’s likely a fake.

Agate Types & Geological Properties of the Agate Crystal

The agate crystal is a microcrystalline-quartz mineraloid that has a lustrous display of multi-color banding and results from long-term accumulations of siliceous groundwater deposits in rock cavities. Much like other mineraloids, all agate types form over thousands of years inside the existing voids of other igneous, sedimentary, and metamorphic rocks that contain silica-rich groundwater. And color formations and patterns can vary depending on numerous environmental factors. In fact, the layering and banding typically visible within an agate gemstone is representative of the shapes of the voids from which it develops. Agate is a popular and highly marketable stone amongst gem enthusiasts worldwide. This is mostly due to its colorful displays, mystifying geological origins, and its spiritual and cultural affiliations. Updated September 10, 2022.

How to Pronounce Agate

Despite the simple spelling of this gemstone, many inquire about its proper pronunciation. Professional geologists at institutions around the world pronounce agate crystal (in the American-English language) as “ae-get.” To demonstrate, the short video below provides a voice-recording of the formal pronunciation.

How the Agate Crystal Got its Name

The name “Agate” relates to the Greek name of the Dirillo River in Sicily, which was “Achates” or “Acate.” In fact, historians believe this is where the semiprecious stone was first discovered by the early earth scientist and Greek Philosopher named Theophrastus. Its initial discovery took place around 371 to 287 BCE. And since then, various cultures value this gemstone for its neat appearance and spiritual affiliations.

Physical Properties of the Agate Crystal

Although this siliceous gemstone isn’t a mineral, geologists still perform the appropriate laboratory tests to report its physical properties, in the same fashion. The following mineral physical properties apply to this mineraloid:

• Color: Variable
• Streak: White
• Luster: Waxy-Flat
• Cleavage: None
• Mohs Hardness Scale: 6.5 to 7.0
• Specific Gravity: 2.6 grams per cubic centimeter (g/cm3)
• Chemical Composition: Variety of microcrystalline form quartz (SiO2)
• Crystal Structure: Amorphous (none)

Various Colors in Agate Types

An agate gemstone can develop to display a variety of common colors. These stones can have numerous shades of one color, or a combination of entirely different colors. For example, in the photograph below, the specimen on the left displays multiple shades of different colors. Whereas the specimen on the right displays various shades of the same color. These color variations are the result of alternating silica composition, pH, and other chemical properties in groundwater at the time of crystallization. In fact, each display of color is the result of different-sized silica spheres. And the color one sees is the material-specific light-reflection property.

Geology of Agate

An agate crystal forms within the cavities of other rocks in acidic to neutral environments. Its formation occurs by the accumulation of silica-rich groundwater in rock voids, over thousands of years. In fact, these chalcedony veins mostly develop within the voids of volcanic igneous rocks and plutonic igneous rocks. This is because igneous rocks have a higher tendency to hold groundwater over long periods of time. As a result, the semiprecious stone forms banding layers over time, that are generally parallel to the surrounding cavity walls.

Although it is possible, this mineraloid is less likely to form within metamorphic rocks and sedimentary rocks due to the lower chance of water retention. To illustrate, such rocks have higher porosity, permeability, and transmissivity properties, and result in groundwater moving through them rather than accumulating within them.

Geological Rock Classification

The agate gemstone is not a sedimentary rock, nor is it metamorphic or igneous. In fact, it isn’t categorizable as any one of the three geologic rock types. Some gem enthusiasts also debate whether it’s a mineral or not. However, in the scientific field of mineralogy, it is generally understood not to be a mineral either, but rather a mineraloid due to its amorphous physical properties and geochemical composition.

Agate is a Type of Chalcedony

The agate gemstone is a type of chalcedony (with translucent physical properties), which is a general name for a microcrystalline quartz and moganite mineraloid. In terms of chemical composition, chalcedony comprises quartz and moganite, which both maintain a silicon dioxide chemical formula, however differ in crystal structure.

What are Silicates

Silicates are compounds with crystal structures that contain SiO4 tetrahedra. Silicates are either isolated or joined to form groups, rings, single or double chains, sheets, or three-dimensional frameworks.

Geodes vs Agate Crystal

Unlike a geode, which similarly forms a series of protruding quartz crystals along cavity walls, the agate types actually develop chalcedony that fully occupies the void space. In some cases, it can crystalize with or within a geode.

Agate Types

All agate types naturally form different patterns and colors on the basis of the environmental factors at the time of crystallization. For example, the most significant factors are rock geochemistry, groundwater content, and pH levels. Additionally, timeframes for crystallization and geologic activity along the way also play a role. Variations in these factors, as well as other environmental components, can shift the formation towards different colors and banding patterns or thicknesses. Thus, producing different agate types.

Firstly, rock geochemistry refers to the mineralogy of the actual rock formation that has the cavities and voids in which the chalcedony develops. As imaginable, the water content and solution changes on the basis of long-term direct contact with a particular rock.

Secondly, the chemical composition of the groundwater itself plays a strong role in the formation of chalcedony. The water-chemistry of the liquid prior to reaching the stagnant and stationary location of the void in a rock, can make the liquid-phase solution further unique. The baseline groundwater chemistry relates to the previous soils that groundwater may have migrated through, as well as the rainwater chemistry prior to percolation.

And lastly, the pH levels of the surrounding soil and groundwater during the long-term process of formation changes the solubility properties of the liquid. And this is the result of numerous environmental factors, including but not limiting to biological influences, depositional climate, metamorphism of surrounding rocks, and more. Thus, an altering pattern of amorphous microcrystalline quartz and moganite forms overtime.

1. Lace Agate Crystal

Lace agate types demonstrate bands, swirls, and concentric circles that make up intricate patterns resembling lace. These types can also comprise a wide variety of color combinations. For instance, the image below is of a blue lace stone.

2. Turritella

This stone gets its name from the voids and cavities of the fossil that it develops within. Turritella snail shells resemble a small unicorn-horn-shape. And when this salacious mineraloid occupies the void spaces, it preserves the Turritells snail fossil.

3. Carnelian Agate Gemstone

One can identify Carnelian agate crystal by its warm hues of red and orange coloration. The banding is less prominent in this type of chalcedony, but it also appears to be more consistent. Moreover, the Carnelian stones appear to be somewhat more-translucent by comparison to the other stone types. However, some gemologists indicate variable translucency factors throughout specimens.

4. Coldwater

The Coldwater stone name comes from its distinct lack of vibrant coloration. The dominant colors of this stone are cloud-white to faint blue. Additionally, there are mute-grey hues that typically swirl throughout this varietal.

5. Greek Achate

In reference to the original discovery of this semiprecious mineraloid, this title relates to the Greek name of the Dirillo River in Sicily, Italy. Colorations range from light to dark grey, red, tan, and blue, with concentric lines trending toward the center.  which can be hollow or closed.

6. Fire Agate Types

Fire agate displays an iridescent coloration resembling mother-of-pearl. In fact, the two share similar properties. Nonetheless, it maintains a combination of bright green, red, yellow, and blue-accenting across a dark background. This can give the fire agate types an appearance much like that of black opal and fire opal. As a result, it tends to be a popular choice amongst collectors.

7. Brazilian

This Brazilian semiprecious stone mostly comes from southern Brazil. This stone is famous for its large size, as well as its circular and geodetic pattern. Naturally, it comprises a variety of colors, such as grey, white, blue, and reddish-brown. However, many street vendors artificially dye and polish them to appear bright pink, light blue, and purple.

8. Polyhedroid

Polyhedroid agate is a rare formation that exists in distinct geometric shapes with straight lines forming triangles and quadrilaterals. However, these shapes are not representative of the “cleavage” property of a crystal, because it is an amorphous mineraloid as opposed to a mineral. Instead, the geometric shapes simply represent the straight lines of the void-walls from which the siliceous groundwater solidifies overtime.

9. Botswana Agate Gemstone

Botswana agate displays grey, mauve, eggplant, and Prussian-blue tones. And this characteristic banding appears to exist throughout most Botswana agate types, worldwide.

10. Plume

The plume stones exhibit a wide range of colors including blue, green, red, and purple, as well as some neutral tones. Nonetheless, an entire pallet of colors can exist in just one specimen. However, this varietal does not display banding, but rather a “plume” pattern. This appears to be similar to a thick smoke billowing from a source point.

11. Condor

Similar to the Plume stone, Condor type stones may showcase the entire spectrum of coloration in one stone. However, unlike the Plumes, this agate does display banding in a concentric fashion. With condors, each band often comprises a different color, to the effect of a brilliant rainbow display.

12. Holley Blue

The Holley Blue Stone gets its name for the pastel tones of blue and purple. It may also contain variations of dark and light bands of color that swirl throughout each specimen.

13. Moss Agate Crystal

The moss agate types get their name from the forest-green and blue-green hues. As the name suggests, the patterns have dark green coloration. It resembles moss growing on a rock.

14. Tube

The tube style stone comprises small and thin columns or “tubes” that form as the mineraloid develops. These formations result in tube-like shapes within the body of the post-crystalization agate. And when the sample is cut into slices, it typically appears with a pattern of cross-sectional circles across the stone.

15. Fortification

Fortification agate refers to the classic banded stone that forms inward from the cavity walls. However, this type may have a hollow center with protruding quartz crystals. The colors can vary, and the name comes from the clearly defined bands resembling layers of walls, or “fortification.”

16. Lake Superior Agate Gemstone

The Lake Superior agate gemstone is distinguishable by its range of red, blue, and white coloration. In fact, Lake Superior agate can range from pale to dark tones. And one common characteristic amongst this type of chalcedony stone is the banding of concentric and swirling patterns.

17. Binghamite

Binghamite is a rare variety of the chalcedony stone that forms in iron ore. The resulting coloration displays red, orange, and gold. Furthermore, most Binghamite has a distinct chatoyant, or reflective property. This is a characteristic most-visible upon polishing the stone.

18. Patuxent River

Patuxent River agate displays warm hues such as pale yellow and peach, as well as deep orange and red. There are usually no bands present, and the colors generally blend smoothly. Additionally, this stone is somewhat translucent, allowing enough light to pass through to give the stone a warm glowing appearance.

19. Enhydro Agate Crystal

Enhydro agate is essentially a mineraloid that is incomplete in the crystallization process. It usually demonstrates a dull bluish-grey color, although all color spectrums are possible depending on the environmental factors. But what makes the enhydro agate types unique is the fact that it contains groundwater inside. In fact, with expert-level cutting and polishing, an enhdryo stone can demonstrate an array of agate coloration and banding, with splashing water inside upon shaking.

Agate Spiritual Meaning & Culture

Like most gemstones, there are cultural and spiritual values with agate crystals, worldwide. Many cultures believe agate has spiritual cleansing power. For instance, agate assists in removing negative energy from one’s life and promotes the harmonious balancing of the mind, body, and spirit. Moreover, it is believed the gem helps clear a person’s mind, giving them the ability to focus on positive goals and tasks. Cultural beliefs also suggest the agate gemstone provides a calming element to a person’s life, allowing them to overcome anger, insecurities, and tension.

Are you interested in learning more about loose beads china manufacturer? Contact us today to secure an expert consultation!