Moonstone
The repetition of thin layers of orthoclase and albite causes light to interfere and reflect within the stone, creating a soft, pearly sheen known as "adularescence."
The beautiful radiance of moonstone
Basic Information
| English Name | Moonstone |
|---|---|
| Japanese Name | Gechoseki |
| Chemical Formula | Mainly Orthoclase, K[AlSi₃O₈] |
| Crystal System | Monoclinic |
| Hardness | 6–6.5 |
| Specific Gravity | 2.6 |
Characteristics & Variations
- Cat's-eye Moonstone: Contains needle-like inclusions that produce a cat's-eye effect.
- Star Moonstone: A rare variety that exhibits a star effect (a cross-shaped reflection).
Origin, Aliases, Treatments, & Similar Stones
Aliases:
- Ceylon Opal: Refers to orthoclase moonstone.
- Oregon Moonstone: A variety of chalcedony from Oregon, USA, whose internal structure gives it an appearance similar to adularescence.
Treatment: Irradiation: Sometimes performed to shift the color from brown to orange.
Similar Stones: Peristerite (albite moonstone), Black Moonstone (a type of labradorite), Rainbow Moonstone (also a type of labradorite).