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Moonstone with Intense Effect
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Moonstone

Plagioclase Feldspars: (Na,Ca)Al1-2Si3-2O8
Orthoclase Feldspar: KAlSi3O8

Hardness
6–6.5
Refractive Index
1.518–1.526
Spec. Gravity
2.56–2.62
System
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Moonstone is the most well-known gemstone of the feldspar group. Named for its glowing color sheen that resembles the moonlight, Moonstone can belong to several different members of the feldspar group, especially Orthoclase and Oligoclase. Moonstone displays a unique play of color known as adularescence. This effect is in the form of a moving floating light or sheen. This phenomenon is caused by structural anomalies within the crystal formation.

About

Moonstone is a fairly abundant and inexpensive gemstone. In addition to its mysterious glow effect, Moonstone often displays a cats eye effect, and the band of light may float upon movement of the stone. Asterism in the form of four-rayed stars also exist, but are less common.

Greater transparency in Moonstone is more desirable, and the more transparency it has, the more valuable it is. The color of the stone also has an impact on its value. Moonstones with a bluish color sheen are very much in demand and are more valuable then the other types. Care should be handled with Moonstone as it is sensitive to pressure and can easily crack or chip.

Uses

Moonstone is an affordable gemstone that is well known since ancient times. It is polished as cabochons and used as beads and pendants. In some societies it is sewn into garments as a charm.
Moonstone, along with Pearl, is the birthstone of June.

Varieties

✓ common  · ✗ uncommon

Treatments & Enhancements

Moonstone gemstones are not treated or enhanced.

Sources

Important deposits of Moonstone exist in India, Sri Lanka, Myanmar (Burma), Australia, Madagascar, Tanzania, and Brazil.

Similar Gemstones

Moonstone has a distinct appearance and it is difficult to confuse with other gemstones. Reddish and brownish Moonstone can look similar to Carnelian but Carnelian lacks the color effect of Moonstone.

Further Reading

Faceted

See all 10 faceted photos →

In the Rough