Photo of Amazonite in Processed & Rough Form
Amazonite is a mineral with a hardness of 6 out of 10 on the Mohs scale of mineral hardness [?]. These Triclinicly structured gems are made of potassium aluminum silicate, their full chemical compound being KAlSi3O8.
Amazonite is a blue-green variety of microcline feldspar, named after the Amazon River (though ironically not found there). Its distinctive color comes from lead and water content. Popular in ancient Egypt and pre-Columbian Central/South America, it's now mainly mined in Colorado, Brazil, and Russia. The stone displays white streaks and can range from bright turquoise to deep green-blue.
What are the diagnostic gemological properties?
Crystal System: Triclinic Refractive Index: 1.514-1.524 Birefringence: 0.008-0.010 Specific Gravity: 2.54-2.57 Hardness: 6-6.5 Mohs Cleavage: Perfect on {001}, good on {010}
What causes the distinctive blue-green color?
Color results from trace amounts of lead and water in the crystal structure. The intensity correlates with lead content, while radiation exposure during formation affects color development. Iron may contribute to secondary hues.
What are the key structural characteristics?
Chemical Formula: Potassium Aluminum Silicate (KAlSi3O8) Structure Type: Framework silicate Distinctive features: Microperthitic texture common Twinning: Common on albite and pericline laws
What are optimal cutting considerations?
Best suited for cabochons due to perfect cleavage Orientation critical to display chatoyancy when present Takes excellent polish but requires care due to cleavage Often cut to preserve distinctive white veining patterns
What distinguishes fine quality material?
Intense blue-green color without grey undertones Even color distribution Distinctive white veining when present Minimal fracturing along cleavage planes High polish capability
What are key locality variations?
Colorado: Often shows white cross-hatched pattern Russia: Typically more intense blue coloration Brazil: Frequently exhibits chatoyancy Madagascar: Generally lighter, more translucent material
What are the stability concerns?
Heat sensitive: May fade at high temperatures Ultrasonic: Not recommended due to cleavage Chemical resistance: Vulnerable to acids Setting requirements: Protective settings recommended for jewelry use
The specific gravity [?] for Amazonite is 2.56, its refractive index [?] is 1.52-1.53, and its double refraction [?] is 0.005.
History
Despite its name, amazonite is not found in the Amazon River basin or region. The name may have originated from tales of green stones found there. Instead it is found in Russia, Madagascar, Brazil, and the United States.
Industrial Usages
Amazonite has limited industrial applications. Its primarily used in jewelry and ornamental objects. Unlike some other feldspars, it's not commonly used in ceramics or glass manufacturing due to its relative scarcity.
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