Turquoise
CuAl6(PO4)4(OH)8·4H2O · Semi-Precious Gemstone and Decorative Stone
Crystal System
Triclinic, typically found in massive, microcrystalline, or botryoidal habits
Mineral Group
Phosphates, specifically the turquoise subgroup
Chemical Formula
CuAl6(PO4)4(OH)8·4H2O
Formation Process
Secondary origin, formed by the action of meteoric waters percolating through copper-bearing aluminum-rich rocks in arid or semi-arid climates
About This Crystal
This carved specimen exhibits a vibrant robin's-egg blue to greenish-blue color with a smooth, polished finish shaped into a stylized bird. It is opaque with a waxy to sub-vitreous luster, featuring a small dark matrix inclusion near the head area.
Physical Characteristics
Color ranges from blue to green; streak is white or pale greenish-blue; cleavage is good in one direction and poor in another, but rarely observed due to massive habit; fracture is conchoidal to uneven; specific gravity ranges from 2.60 to 2.85; tenacity is brittle; typically non-magnetic; can show weak greenish-yellow fluorescence under UV light.
Optical Properties
Biaxial positive with refractive indices typically around 1.61 to 1.65; birefringence is low (approximately 0.040); pleochroism is weak to moderate in shades of light green and blue; it is doubly refractive.
Hardness & Durability
Origin Region
Notable sources include the southwestern United States (Arizona, Nevada, New Mexico), Iran (Nishapur), China, and Egypt (Sinai Peninsula)
Hardness & Durability
Mohs hardness of 5 to 6; toughness is fair to good depending on porosity; sensitive to acids, oils, cosmetics, and excessive heat which can alter its color from blue to green; moderate wearability for jewelry.
Care & Maintenance
Clean gently with warm, soapy water and a soft cloth; avoid ultrasonic cleaners, steam cleaners, harsh chemicals, perfumes, and oils; store separately in a soft pouch away from direct sunlight and harder gemstones to prevent scratching.
Rarity & Value
Uncommon to rare depending on grade, color, and lack of enhancement; natural high-grade spiderweb turquoise commands high prices, while treated, stabilized, or reconstituted turquoise is common and affordable; enhancements like stabilization and waxing are very common.
Special Characteristics
Often features intricate matrix patterns (limonite, sandstone, or quartz) creating spiderweb or butterfly effects; highly prized for its unique sky-blue coloration derived from copper.
Lore & History
Turquoise is one of the oldest gemstones in history, prized by ancient civilizations including the Egyptians, Persians, Native Americans, and Aztecs as a sacred stone of protection, good fortune, and healing. In modern crystal healing, it is often associated with the throat chakra, symbolizing communication, truth, and spiritual balance.