RocksdayApatite vs Aquamarine
How to tell them apart
A calcium phosphate group of minerals — the same family that makes up your teeth and bones.
Photo: Thomas Spann, CC BY 2.0
Pale blue to sea-green beryl, often growing as clean, long hexagonal crystals.
Photo: Gunnar Ries Amphibol, CC BY-SA 2.5
Quick tests
- Scratch glass: Aquamarine scratches glass (Mohs 7.5–8); Apatite can't (Mohs 5).
Key differences
- Blue apatite is much softer.
Side by side
| Property | Apatite | Aquamarine |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 5 | 7.5–8 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Green, Blue, Yellow, Purple | Blue, Green |
| Crystal system | Hexagonal | Hexagonal |
| Specific gravity | 3.16–3.22 | 2.66–2.8 |
| Formula | Ca₅(PO₄)₃(F,Cl,OH) | Be₃Al₂Si₆O₁₈ (with Fe) |
| Found in | Durango, Mexico; Madagascar | Minas Gerais, Brazil; Shigar Valley, Pakistan |
Properties that are the same for both are grayed out.
How to identify apatite
- Six-sided prisms, often with flat ends.
- Hardness 5 — a knife just scratches it.
- Glassy, often yellow-green or neon blue.
- No obvious cleavage.
Crystal system: Hexagonal
Full Apatite guide →How to identify aquamarine
- Sea-blue, glassy six-sided prisms.
- Hardness 7.5–8.
- Often very clean and transparent.
Crystal system: Hexagonal
Full Aquamarine guide →More comparisons
Could you tell them apart from a blurry close-up?
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