Amazonite
Microcline var. Amazonite · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Triclinic; typically occurs in massive, granular, or prismatic habits
Mineral Group
Silicates; Tectosilicate (Feldspar Group)
Chemical Formula
K(AlSi3O8) with trace amounts of Lead (Pb) and Water (H2O) providing color
Formation Process
Igneous; forms via slow crystallization within granitic pegmatites, often under hydrothermal influence where lead and water incorporate into the lattice.
About This Crystal
Opaque to translucent specimen with a signature blue-green to turquoise hue. Features a vitreous to pearly luster and often displays white streaky inclusions or a 'grid-like' schiller effect due to perthitic intergrowth.
Physical Characteristics
Color: Mint green to turquoise. Streak: White. Cleavage: Perfect in two directions at nearly 90 degrees. Fracture: Uneven to conchoidal. Specific Gravity: 2.56-2.58. Fluorescence: Usually inert but can be weak olive-green.
Optical Properties
Refractive Index: 1.522-1.530. Birefringence: 0.008. Biaxial (-) optical character. Often exhibits a silky sheen or schiller effect known as labradorescence (though technically perthitic reflectance).
Hardness & Durability
Origin Region
Notable sources include Russia (Chelyabinsk), Brazil (Minas Gerais), USA (Pikes Peak, Colorado), and Madagascar. Found in granitic pegmatites.
Hardness & Durability
Mohs Hardness: 6.0 to 6.5. Toughness: Poor to fair due to perfect cleavage; sensitive to pressure and sharp blows.
Care & Maintenance
Clean with warm soapy water only. Avoid ultrasonic cleaners and steam cleaning. Sensitive to sudden temperature changes and some acids. Store separately from harder stones like quartz to prevent scratching.
Rarity & Value
Common but high-quality deep teal specimens are sought after. Value is determined by color intensity and uniformity. Generally affordable; treatments like resin impregnation or dyeing are occasionally used.
Special Characteristics
Features 'perthitic texture' (white streaks of albite) and a characteristic shimmering surface luster when rotated, caused by internal lattice structures.
Lore & History
Known as the 'Stone of Hope' or 'Amazon Stone.' Named after the Amazon River, though deposits there are scarce. Used in Ancient Egypt for jewelry and funerary amulets (notably found in King Tutankhamun's treasures).