Comparison · Minerals vs Quartz Family
Epidote vs Quartz
Epidote and Quartz are easy to confuse. Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Epidote and Quartz
- Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Epidote leaves a white to grayish streak on unglazed porcelain, Quartz leaves white.
- Epidote feels noticeably heavier for its size (specific gravity 3.3–3.5 versus 2.65 for Quartz).
- Hold a thin edge to the light: Epidote is Transparent to opaque, Quartz is Transparent to translucent.
- They overlap in yellow and black, but Epidote also comes in green and Quartz also comes in clear, purple, pink, gray, and brown.
- Well-formed crystals give it away: Epidote is Monoclinic, Quartz is Trigonal.
Epidote vs Quartz properties
| Property | Epidote | Quartz |
|---|---|---|
| Type | Minerals | Quartz Family |
| Mohs hardness | 6–7 | 7 |
| Luster | Vitreous | Vitreous, greasy on fracture surfaces |
| Streak | White to grayish | White |
| Transparency | Transparent to opaque | Transparent to translucent |
| Specific gravity | 3.3–3.5 | 2.65 |
| Crystal system | Monoclinic | Trigonal |
| Common colors | Pistachio green, Yellowish green, Dark green, Black | Colorless, White, Purple (amethyst), Yellow (citrine), Pink (rose), Brown/black (smoky) |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $5–$250+ |
Which is more valuable?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $20 for Epidote, and premium Quartz can reach $250 or more.
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.
About Quartz
Quartz is silicon dioxide, SiO2, one of the most abundant minerals in Earth's continental crust, crystallizing in the trigonal division of the hexagonal crystal system with a hardness of 7 that makes it a standard reference point on the Mohs scale. Its six-sided prismatic crystals, often terminated by pyramidal points, are among the most recognizable crystal shapes in mineralogy. Quartz occurs in nearly every rock type and geologic setting, from granite pegmatites to sedimentary sandstones to hydrothermal veins.
Epidote vs Quartz FAQ
Is Epidote the same as Quartz?
No. Epidote is a mineral while Quartz is a quartz family. Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Epidote from Quartz?
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Epidote leaves a white to grayish streak on unglazed porcelain, Quartz leaves white. Epidote feels noticeably heavier for its size (specific gravity 3.3–3.5 versus 2.65 for Quartz).
Which is harder, Epidote or Quartz?
Quartz is harder: Mohs 7 against Mohs 6–7 for Epidote.
Which is more valuable, Epidote or Quartz?
Quartz is usually the more valuable of the two: a typical collector specimen runs about $35 against $20 for Epidote, and premium Quartz can reach $250 or more.
