Amazonite

Amazonite is a green variety of microcline feldspar (KAlSi₃O₈), prized both as a gemstone and for its striking color.

🌍 Origins and Naming

• Name Origin: Named after the Amazon River, though no deposits are actually found there. The name reflects its vivid green color reminiscent of tropical landscapes.
• Mineral Group: Feldspar (alkali feldspar, specifically microcline).
• Discovery: Known since antiquity; used in jewelry and ornamental objects.

🔬 Chemical and Structural Properties

• Formula: KAlSi₃O₈ (microcline feldspar).
• Crystal System: Triclinic.
• Color: Bright green to bluish-green, sometimes mottled with white.
• Cause of Color: Trace amounts of lead and water in the feldspar lattice, plus possible iron content.
• Habit: Blocky crystals, massive aggregates.
• Hardness: ~6–6.5 on Mohs scale.
• Specific Gravity: ~2.56–2.58.
• Cleavage: Perfect in two directions, typical of feldspars.
• Luster: Vitreous.

⚙️ Geological Occurrence

• Found in granitic pegmatites, often associated with quartz, albite, and smoky quartz.
• Localities:
  • Colorado, USA (classic locality, especially Pikes Peak region).
  • Brazil.
  • Madagascar.
  • Russia (Ural Mountains).
  • Namibia.

📖 Scientific and Collector Significance

• Gemstone Use: Cut into cabochons, beads, and ornamental carvings. Rarely faceted due to cleavage.
• Collectors: Valued for its vivid green color and association with pegmatite minerals.
• Industrial Note: No major industrial use; significance lies in gemology and mineral collecting.

✨ Conclusion

Amazonite is a green variety of microcline feldspar, treasured for its vivid color and ornamental use. Found in pegmatites worldwide, it bridges mineralogical interest and gemstone appeal.

In short: Amazonite = green microcline feldspar, triclinic, gemstone from pegmatites, famous in Colorado and worldwide.