Amazonite

Physical Properties

• Hardness: 6.0-6.5
• Luster: Vitreous
• Streak: White
• Diaphaneity: Translucent, opaque
• Specific gravity: 2.56-2.58

Chemical Composition

• Chemical formula: KAlSi
• Polymorphic to orthoclase
• Potassium feldspar called microcline
• Unknown if stones from the Amazon River were amazonite
• No ancient or medieval authority mentions amazonite

Color and Varieties

• Green and greenish-blue varieties are designated as amazonite
• Described as bright verdigris-green and possessing a lively green color
• Occasionally cut and used as a gemstone
• Color may be the aggregate effect of several factors
• Studies suggest the role of lead, rubidium, thallium, and divalent iron in coloration

Occurrence

• Limited occurrence in Bronze Age Egypt and Miass, Russia
• Source of color was a mystery for many years
• Blue-green color may result from lead and water in the feldspar
• Aliovalent lead may play a role in the color of microcline
• Increasing content of lead, rubidium, and thallium associated with color variations

Health Concerns

• Lead leakage from amazonite into an acidic solution exceeded recommended amount
• Experiment simulated a child swallowing amazonite
• Applicable to new wellness practices such as inserting the mineral into oils or drinking water
• Potential health risks associated with high lead content
• Further studies needed to understand the health implications of amazonite

Amazonite Data Sources