azuriet

Azurite is a soft, deep blue copper carbonate mineral and pigment. It is known for its intense azure-blue color, which has made it a valuable pigment in art for centuries. The mineral is formed by the weathering of copper-bearing rocks and is often found in association with malachite, a green copper carbonate. Azurite typically occurs in crystalline form, often as prismatic crystals, or in massive and earthy forms. Its chemical formula is Cu3(CO3)2(OH)2. Azurite is relatively soft, with a Mohs hardness of 3.5 to 4, and has a specific gravity of around 3.8. It is insoluble in water but soluble in acids, producing effervescence. When heated, azurite decomposes into copper oxides. Historically, azurite was ground into a powder to create a vibrant blue pigment used in illuminated manuscripts and paintings. However, it is not as stable as other blue pigments and can transform into malachite over time, especially when exposed to moisture. Today, azurite is primarily valued as a mineral specimen and for its use in jewelry, although its softness requires careful setting. It is found in various locations worldwide, including France, Mexico, and the United States.