Amazonite
Microcline var. Amazonite · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Triclinic, typically occurs as massive aggregates or prismatic crystals
Mineral Group
Silicates (Tectosilicates, Feldspar group)
Chemical Formula
KAlSi3O8
Formation Process
Igneous and pegmatitic formation, crystallizing slowly from cooling magma rich in volatiles, with color often enhanced by irradiation and trace lead.
About This Crystal
A polished, tumbled stone showing a characteristic mottled bright turquoise to blue-green color with whitish schiller-like streaks and patches, opaque transparency, and a vitreous to waxy luster.
Physical Characteristics
Color is bright green to blue-green; streak is white; two directions of good cleavage meeting at nearly 90 degrees; fracture is uneven to conchoidal; specific gravity is approximately 2.56; brittle tenacity.
Optical Properties
Biaxial negative with a refractive index ranging between 1.514 and 1.530; low birefringence; shows weak pleochroism and sometimes a faint adularescent sheen.
Hardness & Durability
Origin Region
Notable sources include Russia (Ilmen Mountains), United States (Colorado), Madagascar, Brazil, and Namibia. Forms mainly in granitic pegmatites.
Hardness & Durability
Mohs hardness of 6; moderate toughness but susceptible to cleavage breakage along planes; sensitive to sharp impacts and rapid thermal shock.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners, steam cleaners, harsh chemicals, and prolonged exposure to high heat or direct sunlight.
Rarity & Value
Common to uncommon depending on color saturation and lack of white matrix; high-grade vivid blue-green material from Russia or Colorado commands higher prices; usually untreated.
Special Characteristics
Often exhibits a distinctive grid-like twinning pattern known as tartan or cross-hatch twinning characteristic of microcline feldspar, alongside characteristic white albite streaks.
Lore & History
Named after the Amazon River though no deposits are found there, historically used in ancient Mesopotamia and Egypt; associated with the heart and throat chakras in modern crystal lore representing truth, soothing, and courage.