Peach Moonstone
Orthoclase var. Moonstone (Potassium Feldspar) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Monoclinic; often found as blocky prismatic crystals or in massive form, though typically seen as tumbled pebbles or cabochons.
Mineral Group
Silicates; Subgroup: Tectosilicates (Feldspar Group)
Chemical Formula
K(AlSi3O8)
Formation Process
Igneous/Metamorphic. Formed from the intergrowth of two types of feldspar (orthoclase and albite) that separate as the magma cools, creating thin alternating layers.
About This Crystal
A translucent to opaque feldspar with a soft peach, apricot, or brownish-orange body color. It exhibits a vitreous to pearly luster and a characteristic glowing surface sheen known as adularescence.
Physical Characteristics
Color: Peach to coral-pink with white sheen; Streak: White; Cleavage: Two directions at nearly 90 degrees; Fracture: Conchoidal to uneven; Specific Gravity: 2.56-2.59; Fluorescence: Weak orange/red (SW) or inert.
Optical Properties
Refractive Index: 1.518-1.526; Birefringence: 0.005-0.008; Notable for adularescence (a billowy white/blue light effect caused by light scattering between feldspar layers).
Hardness & Durability
Origin Region
Madagascar, India, Sri Lanka, and Myanmar; typically found in igneous pegmatites and metamorphic rocks.
Hardness & Durability
Mohs Hardness: 6.0-6.5. Fair toughness; vulnerable to pressure or hard knocks due to perfect cleavage. Suitable for jewelry with protective settings.
Care & Maintenance
Avoid ultrasonic and steam cleaners. Clean with warm, soapy water and a soft cloth. Store separately from harder stones like quartz or sapphire to prevent scratching.
Rarity & Value
Relatively Common. Value is determined by the intensity of the peach color and the strength/visibility of the adularescent sheen. Generally affordable.
Special Characteristics
Adularescence (the 'glow' effect); may occasionally show chatoyancy (cat's eye) or thin black dendritic inclusions as seen in this specimen.
Lore & History
Historically linked to lunar deities and protection during travel. In modern lore, it is associated with the Heart and Sacral chakras, believed to support emotional balance, fertility, and 'feminine' energy.