Rock Identifier
Amazonite (green microcline feldspar) (Microcline, KAlSi₃O₈) — mineral
mineral

Amazonite (green microcline feldspar)

Microcline, KAlSi₃O₈

AI-generated identification · may be incorrect

Blue-green to turquoise, generally opaque, with a vitreous to pearly luster and blocky cleavage surfaces; Mohs hardness 6–6.5, triclinic crystal structure, and specific gravity about 2.54–2.57. The specimen appears rough and naturally fractured, with pale feldspar veining or alteration.

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Physical properties

Blue-green to turquoise, generally opaque, with a vitreous to pearly luster and blocky cleavage surfaces; Mohs hardness 6–6.5, triclinic crystal structure, and specific gravity about 2.54–2.57. The specimen appears rough and naturally fractured, with pale feldspar veining or alteration.

Formation & geological history

Forms in potassium-rich granite and granitic pegmatites during late-stage igneous crystallization, commonly in Precambrian to younger intrusive rocks. Its blue-green color is associated with trace lead, water, and structural defects in the feldspar lattice.

Uses & applications

Used primarily as a decorative stone, cabochon, carving material, and mineral-collection specimen; rarely used in construction because attractive material is limited.

Geological facts

Amazonite is a variety of microcline rather than a separate mineral species. Its color can fade with prolonged intense light or heat, and it is commonly confused with turquoise or chrysocolla.

Field identification & locations

Identify it by turquoise-green color, feldspar cleavage, hardness around 6, and lack of turquoise’s waxy texture or chrysocolla’s softer, often fibrous appearance. Important sources include Colorado, Virginia, Brazil, Madagascar, and Russia.