Most petalite is colorless and glassy looking but some stones are pale yellow and a pink chatoyant specimen has also been reported from South Africa. Little crystalline material is ever available for cutting and faceted stones are uncommon. Large clean stones are always in demand by collectors. The name petalite is derived from the Greek word 'petalos' meaning leaf, an allusion to the cleavage.
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| Known Facts |
| Color Key: |
Colorless, white, gray, yellow, sometimes reddish or greenish white, pink. |
| Refractive Index: |
1.503 - 1.523 |
| Chemical Composition: |
LiAlSiO4O10 |
| Hardness: |
6 - 6.5 |
| Density: |
2.3 - 2.5 |
| Crystal Group: |
Monoclinic |
| Ocurrence: |
North Bonneville Wyoming, Greenwood Maine, San Diego County CA, Bolton MA, USA; Uto, Sweeden; Elba, Italy; USSR; Molo, Myanmar; Londonderry, Western Australia; Arassuahy , Brazil; Bikita, Zimbabwe; Karibib, Namibia. |
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Petalite crystallizes in the monoclinic system. Well formed crystals are rare and most material is massive, tabular, brittle, and cleavable. The luster is vitreous to pearly and the cleavage is perfect in 1 direction.
The name is derived from the Greek petalos, (leaf), in allusion to the cleavage. |
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