Comparison · Minerals vs Silicate Minerals
Epidote vs Zoisite
Epidote and Zoisite 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 Zoisite
- 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, Zoisite leaves white.
- Hold a thin edge to the light: Epidote is Transparent to opaque, Zoisite is transparent.
- They overlap in green, but Epidote also comes in yellow and black and Zoisite also comes in pink, blue, and gray.
- Well-formed crystals give it away: Epidote is Monoclinic, Zoisite is orthorhombic.
Epidote vs Zoisite properties
| Property | Epidote | Zoisite |
|---|---|---|
| Type | Minerals | Silicate Minerals |
| Mohs hardness | 6–7 | 6.5 |
| Luster | Vitreous | vitreous |
| Streak | White to grayish | White |
| Transparency | Transparent to opaque | transparent |
| Specific gravity | 3.3–3.5 | 3.3 |
| Crystal system | Monoclinic | orthorhombic |
| Common colors | Pistachio green, Yellowish green, Dark green, Black | Green, Pink, Blue, Gray |
| Rarity | common | uncommon |
| Typical specimen value | $2–$150+ | $12–$450+ |
Which is more valuable?
Zoisite is usually the more valuable of the two: a typical collector specimen runs about $70 against $20 for Epidote, and premium Zoisite can reach $450 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 Zoisite
Zoisite is a calcium aluminum silicate that occurs in striated prismatic crystals and massive aggregates. Best known through its blue-violet gem variety tanzanite and the pink variety thulite, it is both a metamorphic mineral and a notable gemstone.
Epidote vs Zoisite FAQ
Is Epidote the same as Zoisite?
No. Epidote is a mineral while Zoisite is a silicate mineral. 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 Zoisite?
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, Zoisite leaves white. Hold a thin edge to the light: Epidote is Transparent to opaque, Zoisite is transparent.
Which is harder, Epidote or Zoisite?
They are about equally hard, both near Mohs 6–7.
Which is more valuable, Epidote or Zoisite?
Zoisite is usually the more valuable of the two: a typical collector specimen runs about $70 against $20 for Epidote, and premium Zoisite can reach $450 or more.
