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Jasper vs. Agate: Crucial Differences (Are They Same?)

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Jasper and agate are natural chemical compounds that are debated in science. Scientists cannot conclude whether agate and jasper can be considered the same mineral chalcedony or not. There are scientific arguments in support of both opinions, which we will present in this article.

Today, the prevailing opinion in the scientific community is that agate and jasper are both varieties of chalcedony. Jasper is an opaque variety of chalcedony, and agate is a semitransparent to a semitranslucent variety of chalcedony that is typically banded or striped in appearance.

According to other scientists, agate and jasper are not a type of chalcedony but only contain chalcedony in their composition. In this post, we will look at different views on the issue of agate and jasper, as well as consider various arguments in support of one or another opinion.

Difference Between Jasper and Agate
Difference Between Jasper and Agate

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Are Agate and Jasper the Same

The most common opinion among scholars is that аgate and jasper are not the same minerals but are both varieties of chalcedony, a form of microcrystalline quartz.

A less common opinion is that agate and jasper have a polymineral chemical composition, so it is incorrect to refer them to as chalcedony.

To answer this question, we must look at the definitions of agate and jasper, their properties, and their genesis.

What is Agate

What is Agate
What is Agate

Recent mineralogical and geochemical investigations during the last decades significantly increased our knowledge about the mineralogy and genesis of agates.

According to these recent studies, agates can be regarded as semitransparent to semi-translucent banded chalcedony, which is intergrown or intercalated with other silica phases.

 However, some agates do not have obvious bands. These are often translucent agates with plume-shaped, dendritic, or mossy inclusions.

Moreover, agates often contain considerable amounts of mineral inclusions and water. These impurities may form spectacular internal structures or may be responsible for the different coloration of agates. 

Although agate is considered a mineral, it is often found as a mineral aggregate. When agate forms, it often occurs as a series of concentric bands or layers of different colors and textures, which result from the gradual deposition of mineral materials over time.

Numerous mineralogical investigations have shown that most agates have more than one silica phase and more than one mineral. Chalcedony is the common and dominant form of silica in agates, but except it, there are opal and macro-crystalline forms of quarts. 

In general, it was found that the visible bands are caused by variations in the type of silica phases, their crystal size and habitus, and the porosity and distribution of mineral inclusions (e.g., iron oxides/hydroxides) in the SiO2 matrix.

Conclusion: Essentially, banded agate is composed of several silica minerals, the dominant one being chalcedony. Because of this, agate is considered a type of chalcedony, although other forms of silica are also present in agate.

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Genesis of Agate

Agates are commonly found in areas where volcanic activity has occurred. This is because water rich in dissolved silica flows through fractures and cavities in igneous rocks.

If the solution is highly concentrated with silica, a silica gel can form on the walls of these cavities. Over time, additional gel layers are deposited, forming younger bands of microcrystalline quartz on the walls of the cavity.

Suppose the mineral composition of the silica-rich water changes; impurities other than silicon and oxygen can be incorporated into the gel and the microcrystalline quartz.

These impurities can alter the color of the quartz, creating color banding. In addition, the crystallization of foreign materials can form plumes, dendrites, or mossy structures in translucent agate.

While agates usually form in igneous rocks like basalt, rhyolite, and andesite, they can also form in sedimentary rocks like limestone. As you can see, these types of genesis strip agate.

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Real vs. Fake Agate: You Should Know These 7 Differences

What is Jasper

What is Agate
What is Agate

The term ” jasper” has several definitions, depending on the scientific field and context. Still, the most commonly accepted definition today is this – jasper is an opaque mineral aggregate of microgranular quartz and/or cryptocrystalline chalcedony (to 80%) containing many impurities that determine its opacity and color.   

Because jasper consists of several SiO2 minerals and contains many inclusions, scientists debate whether jasper is a mineral or a rock.

However, here, we must clarify one important thing – the mineralogical term “jasper” and the trade name “jasper” differ.

The fact is that there are rocks that are identical in appearance and physical properties to jaspers but have a slightly different chemical composition. From a mineralogical point of view, this is distinguished as follows:

  1. Jaspers are mostly quartz and chalcedony-quartz (more than 70% of their makeup), and they are made up of changed (metamorphosed) large, micro-granular rocks with a beautiful color that are easy to polish.
  2. Jasperoids are rocks that mostly consist of chalcedony and quartz-chalcedony. They are thought to be volcanogenic-sedimentary rocks that have been strongly changed. They are also poorly changed effusive rocks that contain SiO2 and chert rocks that formed when solutions hit contact with serpentinites and volcanic formations.
  3. Rocks that look like jasper but have a lot of feldspar and quartz-feldspar in them, along with a few chalcedonies (less than 70%)—these are sedimentary and sedimentary-volcanic rocks that are both abiomorphic and biomorphic, made by SiO2 and the remains of silica organisms. Some examples are lydites, which have a mostly chalcedony composition, phtanites, which have a predominantly quartz composition, and tuffites. But experts haven’t decided for sure what to do about this yet. Some experts say that these three names are different, while others say that only jasper and jasperoid are different. Still, some people only know “Jasper” for all of these things.

It’s a lot easier when it comes to the business term “jasper.” According to the business world, jasper includes real jasper, jasperoids, and rocks that look like jasper.

All of them have some things in common, like bright colors, interesting designs on the surface, high hardness (at least six on the Mohs scale), a micro-cryptocrystalline structure, density, opacity, and the ability to be worked and polished to a mirror finish. Small differences in the chemical makeup are not taken into account.

Let’s get rid of all the details about the chemicals that make up jasper and make the description as simple as we can. In that case, it will look like this: Jasper is an opaque type of chalcedony.

Nothing can see through opaque things, not even light. It’s as easy and clear as it can be, but it won’t be right all the time.

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Genesis of Jasper

Jasper’s genesis is also an important issue. The way jasper is formed explains many inclusions and the unique appearance that distinguishes it from other types of chalcedony, including agate.

The most common theory of the genesis of jasper is the one that says that jasper is rocks or mineral formations, which are to be considered mainly among the metasomatic products as a result of metasomatism and recrystallization of the primary sedimentary-volcanic, effusive, or intrusive rocks during the processes of metamorphism”.

The theory of sedimentary jasper formation is also widespread. While agate usually forms in the cavities of igneous rocks or limestone, jasper often forms when finely dispersed materials are cemented by silica.

This often occurs in soft sedimentary rocks when silica precipitates and cements them into a solid mass. These incorporated particles give jasper its color and opacity.

Jasper is also known to form when volcanic ash or fine pyroclastic material is cemented into a solid material from precipitated silica that falls out of solution.

The cementation process is sometimes so aggressive that the sediment, ash, or volcanic particles dissolve or recrystallize into microcrystalline quartz.

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Identifying Real Jasper Mineral (Step-by-Step Guide)

Is Jasper in the Agate Family

Let’s take the view that jasper is an opaque type of chalcedony. We also accept the statement that agate is a striped type of chalcedony. Based on this, Jasper is a member of the agate family. 

But if we take into account the fact that agate and jasper are poly mineral formations with different contents of certain minerals, we can argue that they are different mineral formations that do not belong to the same family. At the moment, this issue is still controversial among scientists.

What Is the Difference Between Jasper and Agate

Assume for the moment that jasper and agate are both forms of the mineral chalcedony. This means that agate’s and jasper’s physical and chemical characteristics will be identical. So, how do we distinguish between these two species?

The answer is simple – by appearance. Although they have some similarities in appearance, a few key differences will help you distinguish them. The first is transparency. Remember, jasper is completely opaque, while agate is translucent. The second is a characteristic pattern.

  1. Agate and Jasper are both clear, which is the first big difference between them. Agate is see-through, but Jasper is completely solid. On the other hand, it can be hard to tell the difference between clear and dark. Some types may also have areas that are see-through and areas that are not. What do you call them? To get around this issue, some people call something “jaspagate” or “jasper-agate” if it has both jasper and agate areas.
  2. Second, both Jasper and Agate are well-known for the way they look. Bands are what make agate stand out. Its stripes make a lot of different designs. The most common types have stripes grouped in rings or straight lines next to each other. We already understand that this is what Genesis led to.

But not all types of agates have stripes. For example, mossy agate has no striations; instead, it is known for tree-like patterns on the surface, which are formed by mineral dendrites. The so-called grape agate is also known for its characteristic shape reminiscent of grape bunches.

Jasper will be more difficult, as jasper can also be striped with various fancy patterns. However, as a rule, these patterns are somewhat different from the characteristics of agate. Together with opacity, this creates an appearance that is not typical for agates.


Agate and jasper are words that people have known for a very long time. At that time, no one knew the exact details of their chemical makeup and agate and jasper could be told apart by how they looked.

In the end, experts found that these minerals come from chalcedony, a type of microcrystalline quartz. This is the reason why agate and jasper are both types of chalcedony.

With the progress of technology, however, scientists now have the tools they need to figure out exactly what chemicals are in these natural molecules.

This led to the discovery that agate and jasper are not made up of just one crystal but of several. Because of this, experts aren’t sure if agate and jasper belong in the same group as chalcedony or not.

Today, the prevailing opinion in the scientific community is that agate and jasper are subspecies of the mineral chalcedony. The key differences are in their different genesis, transparency, and characteristic appearance.


  1. O. Geleta, W. Nesterovsky, 2020 – Jasper and its decorative varieties
  2. Barsanov, Yakovleva – Mineralogy of jasper of the USSR, 1978    
  3. Jens Götze, Robert Möckel and Yuanming Pan, 2020 – Mineralogy, Geochemistry and Genesis of Agate
  4. Ruslan I. Kostow, 2010 – Review on the mineralogical systematics of jasper and related rocks

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Identifying Minerals and Rocks at Home (Step-by-Step Guide)