Comparison · Minerals
Calcite vs Epidote
Calcite and Epidote are easy to confuse because both are minerals. 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. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Calcite and Epidote
- 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.
- Streak color differs: Calcite leaves a white streak on unglazed porcelain, Epidote leaves white to grayish.
- Epidote feels noticeably heavier for its size (specific gravity 3.3–3.5 versus 2.7 for Calcite).
- Hold a thin edge to the light: Calcite is transparent, Epidote is Transparent to opaque.
- They overlap in yellow and green, but Calcite also comes in clear, orange, blue, and pink and Epidote also comes in black.
- Well-formed crystals give it away: Calcite is trigonal, Epidote is Monoclinic.
Calcite vs Epidote properties
| Property | Calcite | Epidote |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3 | 6–7 |
| Luster | vitreous | Vitreous |
| Streak | White | White to grayish |
| Transparency | transparent | Transparent to opaque |
| Specific gravity | 2.7 | 3.3–3.5 |
| Crystal system | trigonal | Monoclinic |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | Pistachio green, Yellowish green, Dark green, Black |
| Rarity | common | common |
| Typical specimen value | $2–$100+ | $2–$150+ |
Which is more valuable?
Epidote is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Epidote can reach $150 or more.
About Calcite
Calcite is one of the most common minerals on Earth, found in sedimentary, metamorphic, and igneous rocks. It's the primary component of limestone and marble.
About Epidote
Epidote is a calcium aluminum iron sorosilicate with the approximate formula Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH), instantly recognizable to many collectors by its distinctive pistachio-green color. It crystallizes in the monoclinic system, typically as elongated, striated prismatic crystals. The color and composition vary with the ratio of iron to aluminum, grading toward the related mineral clinozoisite as iron decreases.
Calcite vs Epidote FAQ
Is Calcite the same as Epidote?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. 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.
How can you tell Calcite from Epidote?
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. Streak color differs: Calcite leaves a white streak on unglazed porcelain, Epidote leaves white to grayish. Epidote feels noticeably heavier for its size (specific gravity 3.3–3.5 versus 2.7 for Calcite).
Which is harder, Calcite or Epidote?
Epidote is harder: Mohs 6–7 against Mohs 3 for Calcite.
Which is more valuable, Calcite or Epidote?
Epidote is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Epidote can reach $150 or more.
