Peach Moonstone
Potassium Feldspar var. Orthoclase (Adularia) · Semi-Precious Gemstone
Crystal System
Monoclinic; commonly occurs in massive or tumbled form, but prismatic as a mineral
Mineral Group
Silicates; Tectosilicates (Feldspar Group)
Chemical Formula
KAlSi3O8 (with trace inclusions of hematite or goethite)
Formation Process
Igneous/Metamorphic; forms as a result of magmatic crystallization in pegmatites or in regional metamorphic rocks
About This Crystal
A tumbled, rounded stone with a soft peach to salmon-pink color. It exhibits a pearly to vitreous luster and a translucent to opaque clarity. The surface shows cloudy white mottling and characteristic internal veining
Physical Characteristics
Color: Peach/Salmon; Streak: White; Cleavage: Two directions at 90 degrees; Fracture: Uneven to conchoidal; Specific Gravity: 2.56-2.59; Tenacity: Brittle; Fluorescence: Weak orange or blue under UV
Optical Properties
Refractive Index: 1.518-1.526; Birefringence: 0.005-0.008; Optical Phenomenon: Adularescence (a ghostly glow or sheen caused by light scattering between alternating layers of orthoclase and albite)
Hardness & Durability
Origin Region
Madagascar, India, and Sri Lanka; found in pegmatite and metamorphic deposits
Hardness & Durability
Mohs Hardness: 6.0 - 6.5; Toughness: Poor due to perfect cleavage; vulnerable to sharp blows and pressure
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic or steam cleaners. Store separately to prevent scratching by harder stones like quartz or sapphire
Rarity & Value
Common; value is determined by the strength of the sheen, color saturation, and lack of visible cracks. Generally affordable and often left as polished tumble stones or beads
Special Characteristics
Adularescence (schiller effect); sometimes shows a subtle cat's eye effect (chatoyancy) or a floating light phenomenon called 'shiller' caused by light interference
Lore & History
Historically associated with lunar energy and fertility in many ancient cultures. In modern crystal healing, it is traditionally used to represent emotional support, intuition, and the 'Divine Feminine' associated with the sacral chakra