For rockhounds with a particular soft spot for the color green, serpentine and epidote can be rewarding stones to seek out.
Because of their similar color palette, these two specimens are frequently confused for one another.
However, as we will see over the course of this article, there are several key differences between these two stones that will allow even novice rockhounds to sort them with ease as long as they look for the following crucial features in an unidentified specimen.
Epidote vs Serpentine (EXPLAINED)
What Is Serpentine?
Serpentine, also known as serpentinite, is an overarching category of minerals that contains over twenty different minerals that share closely related elemental structures.
They typically consist of a general hydrous magnesium iron phyllosilicate formula that incorporates hints of nickel, aluminum, iron, and manganese, as well as silicon.
When a rock consists of multiple forms of serpentine, professional geologists label the specimen as serpentinite.
Although serpentine can contain traces of metallic compounds in its makeup such as nickel and aluminum, the gem itself is not considered a metal. In plain terms, serpentine is a spotted, green-tinged, or brownish mineral and gem that some believe earns its name from its serpent-like color.
Serpentine usually possesses a waxy, slippery finish, but it can look granular or fibrous despite its smooth feel.
Its specific gravity ranges from about 2.5-3.2. Additionally, serpentine places around 5.5-6 on the Moh scale for hardness.
In practice, these minerals are harvested for their usefulness in products related to asbestos, magnesium, and crystal collecting home decor.
Because of their asbestos content, which is a known public health hazard, the law limits their utilization in landscaping in some regions.
Because of their beauty and unique qualities, California overlooks their implications on public health and still claims them as their official state rock.
Because serpentine contains asbestos and therefore, when consumed, holds the potential to harm the ingestor, it is recommended that folks who identify a rock similar to serpentine keep it away from their mouths, small children, and wash their hands after touching it.
Asbestosis is a serious lung condition which can be fatal and therefore, caution around this material is vital for public and personal safety.
Where Can Rockhounds Find Serpentine?
When on the hunt for this pretty, practical stone, delve into California, Arizona, and New Jersey through their mountains and along the coastlines.
When rockhounding in these areas, be sure to bring specimen bags, a small spray bottle, flashlight, small trowel, and water-friendly footwear.
From an international perspective, it’s best to seek this mineral in parts of Italy, Greece, and notoriously Quebec, Canada.
Therefore, wanderlust rockhounds on the hunt for serpentine should be sure to check out these destinations.
What Is Epidote?
Epidote is also a typically greenish, yellowish, or black-tinted stone with a vitreous to resinous luster and colorless streak.
This gem is also termed “Pistacite” for it’s color that resembles a favorite green snacking nut.
Chemically speaking, epidote is usually composed with a formula oCa2(Al,Fe)2(SiO4)3(OH) and a basic calcium aluminum iron silicate composition.
Sometimes specimens of this silicate mineral variety will possess cleavage that follows a perfect pattern in one direction–other times the pattern is imperfect.
On the Moh scale, this stone averages a 6 to 7 hardness. Epidote’s specific gravity runs between 3.3 and 3.5.
These characteristics, along with its unique coloring, allow amateur and professional rock lovers alike to pick epidote out from the pack.
This pistachio-toned semi-precious gem occupies a classic space in many fine gem collections around the world.
While the industrial sector has little use for this stone, avid gem and mineral enthusiasts enjoy having this earthy green stone faceted into jewelry or displayed among their other treasures.
Jewelry designers will sometimes cut this rock with other gems or take advantage of its natural occurrence in metamorphic rocks such as episodite.
Where Can Rockhounds Find Epidote?
In the United States, Epidote abounds in North Carolina, where it was first discovered, along with Virginia and, in particularly gorgeous varieties, in Alaska.
Epidote also occurs naturally in parts of Nevada, Vermont, and New Jersey.
No matter what coast a rockhound calls home–North, South, East, or West–epidote is sure to lie in easy road-tripping distance.
Abroad, one can find epidote as far as the European Alps to Pakistanian clefts.
France, North Africa, and Brazil have also produced lovely specimens of epidote in rockhounding history.
This mineral is not particularly rare, but its beautiful coloring makes it a worthwhile encounter, nonetheless.
Rockhounds can spot this mineral as a secondary element in metamorphic rocks such as in limestone as well as through contact zones between igneous and calcareous sedimentary rocks.
Sometimes, epidote even occurs within other gems such as quartz or calcite.
This rock frequently gets mistaken for tourmaline and vesuvianite. It also gets mixed up with serpentine, which we will discuss in the next point.
Why Do Some People Confuse Epidote and Serpentine?
Often, epidote and serpentine get confused due to their similarities in coloring and their slightly metallic qualities as minerals.
For example, both stones have white or colorless streaks and green, black, or light brown undertones.
Also, both stones are found in metamorphic rocks. For the casual collector, these stones have similar decorative purposes and prevalence.
These qualities can make the two specimens hard to differentiate.
How Can Rockhounds Tell Epidote and Serpentine Apart?
Although they have similar coloring, epidote and serpentine possess different textures. Serpentine is waxy and slippery whereas epidote takes on a smoother texture.
Epidote frequently boasts a sort of glassy finish. Serpentine, on the other hand, is decidedly buttery.
Also, serpentine is strictly a metamorphic rock while epidote can manifest as an altered igneous rock or metamorphic rock occurrence.
Their hardness on the Moh scale is pretty close, but epidote tends to run slightly harder.
Serpentine also shows a lower specific gravity on average than its epidote counterparts.
In crystal form, epidote tends to take on long, slender connected prismatic shapes.
Dissimilarly, serpentine crystallizes into masses, flat plates, and fibrous grains.
Sometimes epidote does grow in segments of serpentine, so unfortunately, when an unidentified specimen seems to take on both stones’ properties, it may be due to the specimen actually being a combination of them.
However, when in doubt, a skilled mineralologist from a local gem and mineral club or rock-hounding organization can steer stumped rockhounds in the right direction.
In conclusion, epidote is a type of silicate mineral that populates almost every corner of the globe.
It comes in a wide range of colors, most popularly green, and is highly desirable to gem and mineral collectors and jewelers, but not very useful outside of its beauty.
Serpentine, an umbrella term for a collection of minerals with similar compositions, looks similar to epidote due to its greenish tint.
However, serpentine contains the toxin asbestos and is ultimately different in its finish and crystal formation.
The two rocks can be similar in appearance to the untrained eye, but their chemical composition and texture differentiate them in most cases.
Sometimes, epidote forms in serpentine, making the distinction further complicated.
However, a professional gem or mineral specialist can distinguish the two if a hobbyist rockhound finds it impossible.
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