THE MATERIAL LIBRARY
Moonstone
A feldspar gem with a floating, soft sheen called adularescence.
Colors & patterns
White, cream, peach, gray and other body colors, often with white or blue sheen.
Typical origins
Sources include Sri Lanka, India and Madagascar.
Hardness
6–6.5 on the Mohs scale.
Choosing & setting this material
The sheen changes with lighting and cutting orientation. Rainbow moonstone is commonly a labradorite variety; ask which feldspar is being offered and protect it from knocks.
Care & cleaning
Clean gently with lukewarm water, a little mild soap and a soft cloth, then dry. Avoid steam, ultrasonic cleaners, harsh chemicals and sudden temperature changes, especially when treatments are unknown.
Origins above describe typical sources of the material, not the origin of an illustrated or stocked stone. Hardness measures scratch resistance, not resistance to breaking. Confirm the identity and treatments of the actual piece.
Further reading: Material reference · GIA: gem treatments