Natural stones, the likes of peridot and epidote come in various sizes and shapes, but sometimes it’s hard to tell the difference between them because of their similar characteristics.
To help you know better, we’ll be comparing their similarities as well as diving into the debate of what makes them different from one another.
Peridot vs Epidote: EXPLAINED
A peridot, also called a chrysolite, is a magnesium-rich variety of a gem-like olivine and a silicate mineral with a green color.
The pigmentation of peridot’s green color comes from the rich iron content within the rock, and it can be found in the molten core of the upper mantle, mainly in silica-deficient rocks such as volcanic basalt.
Peridot is a gem-stone that occurs in only one pigment; olive green, however, the color can range from yellow to brownish green, depending on the amount of iron embedded within the structure.
Not only that, you’d rarely find gem-quality peridot on the surface of the earth, due to it being vulnerable to weathering.
An epidote is a silicate rock with a crystalline structure of silica tetrahedrons.
It is mainly found within metamorphosed ingenuous rocks and basalts, being the hydrothermal alteration of the various minerals present within these rocks.
Epidote is mostly used as a gemstone despite its glass-scratching properties, and can be found at rare geographical locations.
Epidote pigmentation is that of a transparent olive green, however, its color depends on the iron content within the crystal-like structure, ranging from yellow-green to pistachio and brown-green.
The rock has a resinous luster in a monoclinic system, being prismatic in habit.
How are peridot and epidote similar to one another?
Peridot and epidote, being gem-like rocks from the same mineral group, have a lot of similarities to each other in terms of physical features, chemical properties, composition, and pigmentation:
1. History – being two of the oldest gem-stones, both peridot and epidote’s discovery dates over a thousand years, and they’ve been mined ever since, making various historical appearances in between.
2. Appearance – both peridot and epidote have an olive green color, and a rugged or rough appearance with small chips or cracks, gaps within the structure, and blatant discoloration (brown, yellow or dark green).
3. Pigmentation – with a highly similar olive green color, ranging from yellow-green to brownish-green, their color depends on the level of iron richness within the structure of the gem-like stone.
How to differentiate between a peridot and an epidote?
While they may have their own respective similarities, peridot and epidote do differ within the specificities of their own individual features:
1. Appearance – their olive-green color may look similar, but their appearance is not. Peridots are highly pigmented and are commonly a very dull olive green, while epidote can also be a very dark color. Peridots are opaque, while epidote is translucent and see-through.
2. Chemical contents – their chemical composition differs where some chemicals are of concern, for example, while peridot is rich in magnesium, epidote is not. Similarly, epidote contains aluminum traces while peridot does not.
3. Physical properties – while both are hard rocks, peridot being an orthorhombic crystal has a more rounded off and polished structure, whereas epidote, being a crystalline structure of silica tetrahedrons is more sharp-edged and textured.
4. Value and pricing – a 1 carat peridot stone’s price ranges from 60-80$, whereas a peridot stone of the same carat gets sold for around 10-80$, hence a peridot stone holds more value than an epidote.
5. Potential industrial uses – peridot is used in metallurgical processes and to remove impurities by being added to blast furnaces, whereas epidote does not have any significant industrial uses except for being cut into faceted stones.
6. Location and occurrence – peridot is found mostly in Southeast Asia (China, Pakistan) and in northern Africa, while epidote is mined only in the US. Peridot is formed within volcanic rocks and meteorites, whereas epidote is formed within metamorphic rocks and basalts.
Why do so many people confuse peridot and epidote together?
Peridot and epidote, being from the same mineral family sometimes get confused for each other because of their various similarities (color, appearance and chemical composition), however, once you know how to tell apart the teeny tiny differences (translucence, occurrence and structure), you can learn how to differentiate between the two.
The main confusion that occurs is because of the very similar olive-green pigmentation of a peridot and an epidote, this confusion can be resolved by looking at both the rocks through a loupe or a professional magnifying glass.
The main features you should look out for are the outward appearance (polished, translucent or crystalline), and any cracks or discoloration embedded within the structure of the rock.
If you’re someone who enjoys exploring the outdoors, venturing into the unknown or a geologist interested in rock hounding, you have one thing in common; your love for the various types of pigmented rocks nature has to offer.
As a rock collector, a geologist-to-be, or just someone who’s interested in naturally occurring phenomena and material such as rocks and minerals, it’s important that you know how to differentiate between the types of rocks that may look very similar in the first glance, but on closer look appear to be as different as they can be.
After reading this, we hope you acquire a know-how of what kind of stone peridot and epidote are, their features (both physical and chemical), their similarities, and the ways in which they differ from one another.
This will help you classify them accurately and properly on your next geographical adventure and many more to come in the near future.
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