Azurite
“Deep blue copper treasure”
Azurite is a striking deep blue copper carbonate mineral that has been prized as a pigment and gemstone for thousands of years. It commonly forms alongside malachite in the oxidation zone of copper deposits, and over time it often slowly transforms into green malachite.
copper carbonate hydroxide (Cu₃(CO₃)₂(OH)₂)
Tsumeb (Namibia), Bisbee (Arizona, USA), Chessy (France), Touissit (Morocco), Liufengshan (China)
3.5-4
Many Renaissance paintings that originally featured brilliant blue skies now appear greenish because the azurite pigment used has slowly converted to green malachite over the centuries.
Test Your Knowledge
Why have many Renaissance paintings with blue skies gradually turned green over the centuries?
Related Specimens
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