RocksdayAlbite vs Petalite
How to tell them apart
The sodium-rich plagioclase feldspar. In pegmatites it forms white platy crystals that often host tourmaline and other gems.
Photo: Rock Currier, CC BY 3.0
A lithium aluminum silicate from pegmatites, usually white or colorless.
Photo: Eurico Zimbres, CC BY-SA 2.5
Key differences
- Albite shows fine striations on its cleavage faces.
Side by side
| Property | Albite | Petalite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 6–6.5 | 6–6.5 |
| Luster | Vitreous to pearly | Vitreous to pearly |
| Streak | White | White |
| Colors | White, Clear | Clear, White, Pink |
| Crystal system | Triclinic | Monoclinic |
| Specific gravity | 2.6–2.65 | 2.39–2.46 |
| Formula | NaAlSi₃O₈ | LiAlSi₄O₁₀ |
| Found in | Minas Gerais, Brazil; Gilgit-Baltistan, Pakistan | Bikita, Zimbabwe; Karibib, Namibia |
Properties that are the same for both are grayed out.
How to identify albite
- White, platy or bladed crystals.
- Fine parallel striations on cleavage faces.
- Hardness about 6.
Crystal system: Triclinic
Full Albite guide →How to identify petalite
- Colorless to white with a pearly cleavage face.
- Light in weight.
- Hardness about 6.
Crystal system: Monoclinic
Full Petalite guide →More comparisons
Could you tell them apart from a blurry close-up?
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