Yellow Moonstone / Peach Moonstone
Orthoclase var. Moonstone (Potassium Aluminum Silicate) · Semi-Precious Gemstone / Collector Mineral
Crystal System
Monoclinic; typically found in massive, tumbled, or rounded form to showcase optical effects.
Mineral Group
Silicates (Tectosilicates / Feldspar Group)
Chemical Formula
(K,Na)AlSi3O8 with trace elements of Iron(Fe)
Formation Process
Igneous formation; develops through slow cooling of magma where orthoclase and albite separate into microscopic layers.
About This Crystal
A translucent to opaque tumbled stone featuring a creamy peach-to-yellow body color. It exhibits a soft, pearly to vitreous luster with internal cloud-like mottling and subtle schiller effect.
Physical Characteristics
Color: Peach/Yellow/Cream; Streak: White; Cleavage: Two directions at 90 degrees (often hidden in tumbled stones); Specific Gravity: 2.56-2.59; Weak blue/orange fluorescence.
Optical Properties
Refractive Index: 1.518-1.526; Adularescence (soft internal glow caused by light scattering between feldspar layers); Biaxial negative.
Hardness & Durability
Origin Region
Madagascar, Sri Lanka, India, and Tanzania; typically found in igneous pegmatites.
Hardness & Durability
Mohs hardness 6.0-6.5; Brittle tenacity; Fair durability but prone to scratching if stored with quartz or harder gems.
Care & Maintenance
Avoid ultrasonic and steam cleaners; clean with warm soapy water and soft cloth. Sensitive to sudden temperature changes and harsh acids.
Rarity & Value
Common to Uncommon; Value is dictated by the strength of the sheen/adularescence and intensity of color. Generally affordable in tumbled form.
Special Characteristics
Adularescence (billowy light effect); can rarely show chatoyancy or asterism if cut correctly; some specimens feature internal 'centipede' inclusions.
Lore & History
Traditionally associated with lunar deities and feminine energy. Used historically as a traveler's stone for protection. Believed in lore to enhance intuition and emotional balance.