Peach Moonstone
Orthoclase Feldspar (KAlSi3O8)
Rock Type: mineral

Physical Properties
Hardness: 6-6.5 Mohs; Color: Peach, salmon, or orange-beige; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Specific gravity: 2.56-2.58; Features adularescence (a glowing sheen).
Formation & Geological History
Formed in igneous and metamorphic rocks when cooling magma allows feldspar layers to separate (exsolution), creating the structure that scatters light. Often found in pegmatites.
Uses & Applications
Primarily used in jewelry (cabochons, beads, rings), ornamental carvings, and as a popular specimen for crystal healing and mineral collecting.
Geological Facts
The 'glow' associated with moonstone is called adularescence, which is caused by the interference of light reflecting off internal structures of albite and orthoclase feldspar.
Field Identification & Locations
Identify in the field by its distinct pearly luster and the way light seems to move across the surface when tilted. Commonly found in Madagascar, Sri Lanka, and India.
Identified on: 4/27/2026
Mode: Standard