Amazonite
Microcline var. Amazonite · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Triclinic; typically occurs in blocky crystals or massive forms. It frequently exhibits perthitic textural intergrowths.
Mineral Group
Silicates (Tectosilicate), Feldspar group, Alkali Feldspar subgroup
Chemical Formula
K(AlSi3O8), colored by trace amounts of lead (Pb) and water (H2O)
Formation Process
Igneous/Magmatic; primarily forms in granitic pegmatites and hydrothermal veins under deep-seated crustal conditions.
About This Crystal
A vibrant blue-green to teal green stone, often showing a mottled or 'schiller' effect. This specific tumbled specimen displays characteristic white streaks known as perthitic texture. It is opaque to translucent with a vitreous to pearly luster.
Physical Characteristics
Color: Teal, green, or blue-green with white streaks. 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 sometimes weak olive-green or weak pink under UV.
Optical Properties
Refractive Index: 1.522-1.530. Birefringence: 0.008. Biaxial (-) optical character. Often exhibits a silky or pearly sheen caused by internal structural intergrowths (perthitic texture).
Hardness & Durability
Origin Region
Brazil (Minas Gerais), Russia (Ural Mountains), USA (Colorado), Madagascar, and Ethiopia.
Hardness & Durability
Mohs Hardness: 6.0 to 6.5. Toughness is poor due to perfect cleavage; it is brittle and sensitive to pressure and sharp blows.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners and steam cleaners. Sensitive to sudden temperature changes and strong acids. Store separately to prevent scratching.
Rarity & Value
Relatively common but high-quality deep teal specimens are more valuable. Price is generally affordable. It is occasionally stabilized with resin to improve durability or dyed to enhance color.
Special Characteristics
Perthitic texture: The white streaking is caused by the separation of albite (sodium feldspar) from microcline (potassium feldspar) during cooling.
Lore & History
Named after the Amazon River, though it is not found there today. Historically used in Ancient Egypt for jewelry and amulets (King Tutankhamun's funeral mask included it). In lore, it is called the 'Stone of Hope' and associated with the Heart and Throat chakras.