RocksdayEmerald vs Olivine
How to tell them apart
Green beryl colored by chromium or vanadium — one of the four classic precious gems.
Photo: Géry PARENT, CC0
Olive-green silicate that makes up most of Earth's upper mantle. Gem-quality olivine is called peridot.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Quick tests
- Heft: Olivine feels noticeably heavier for its size (specific gravity 3.2–4.4 vs 2.67–2.78).
Key differences
- Peridot is yellowish green and grainy, not prismatic.
Side by side
| Property | Emerald | Olivine |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 7.5–8 | 6.5–7 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Green | Green, Yellow |
| Crystal system | Hexagonal | Orthorhombic |
| Specific gravity | 2.67–2.78 | 3.2–4.4 |
| Formula | Be₃Al₂Si₆O₁₈ (with Cr/V) | (Mg,Fe)₂SiO₄ |
| Found in | Muzo and Chivor, Colombia; Kafubu, Zambia | Papakōlea, Hawaii; San Carlos, Arizona |
Properties that are the same for both are grayed out.
How to identify emerald
- Deep green six-sided prisms with flat ends.
- Almost always has internal fractures and inclusions.
- Hardness 7.5–8.
Crystal system: Hexagonal
Full Emerald guide →How to identify olivine
- Bottle- to olive-green glassy grains.
- Often as sugary green clumps in black basalt.
- No cleavage — breaks like glass.
- Hard enough to scratch glass.
Crystal system: Orthorhombic
Full Olivine guide →More comparisons
Could you tell them apart from a blurry close-up?
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