Identification guide · Minerals
How to Identify Epidote
Epidote typically appears pistachio to olive green, occasionally brown or black, with a vitreous luster and one perfect cleavage direction. Crystals are elongated and prismatic with fine striations running parallel to their length. Hardness is 6 to 7, streak is colorless to gray, and pleochroism is often visible as a shift between green, yellow, and brown. It can resemble actinolite or tourmaline, but its distinctive green tone and single good cleavage, rather than the amphibole's two, usually settle the identification.
Epidote identification checklist
| Color | Pistachio green, Yellowish green, Dark green, Black | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Transparent to opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 6–7 | It scratches glass and a steel knife and cannot be scratched by a steel file. |
| Streak | White to grayish | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Perfect, one direction (basal) | |
| Fracture | Uneven to conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 3.3–3.5 | Heavier than it looks (specific gravity about 3.4). |
| Crystal system | Monoclinic |
Extra tests for Epidote
Glass check. Epidote shares a glassy luster and conchoidal fracture with man-made glass. Glass sits near Mohs 5.5 and often contains round gas bubbles, so a hardness test and a hand lens separate them.
Epidote look-alikes and how to tell them apart
Epidote is harder (Mohs 6–7) than Calcite (Mohs 3), so Epidote will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Epidote vs Calcite →
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Epidote vs Andradite →
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Epidote vs Quartz →
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Epidote identification FAQ
How can you tell if a rock is Epidote?
Check the color (pistachio green, yellowish green, dark green, and black), the vitreous luster, a Mohs hardness of 6–7 and a white to grayish streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Epidote?
Epidote has a Mohs hardness of 6–7. It scratches glass and a steel knife and cannot be scratched by a steel file.
What is the difference between Epidote and Calcite?
Epidote (Mohs 6–7, vitreous luster) and Calcite (Mohs 3, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Epidote vs Calcite comparison for a side-by-side table.
Is Epidote worth anything?
Entry-level Epidote specimens sell for around $2, typical collector pieces about $20, and premium examples $150 or more depending on size, quality and locality.
What color is Epidote?
Epidote is most often pistachio green, yellowish green, dark green, and black. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
