Overall Dimension (including bail): 1.75 x 1 x 0.3 inches
Inner Bail Diameter: 4 mm
Weight: 10.8 grams
Stamp/Mark: Starborn, 925
Serial Number: p29641
Moonstone is a variety of orthoclase, a feldspar. It often has a sky blue opalescent sheen, also called schiller or fire, making the stone look as if it is glowing. The sheen is created by thin layering of orthoclase with another mineral, albite. Moonstone was used in jewelry from 100 AD in Rome and even earlier in Asia.