Azurite

Azurite is a deep-blue copper carbonate hydroxide mineral, Cu₃(CO₃)₂(OH)₂, that forms in oxidized copper deposits and has been ground into pigment.

Copper(II) carbonate hydroxide: A chemical composition containing copper(II), carbonate, and hydroxide ions. Azurite’s formula, Cu₃(CO₃)₂(OH)₂, identifies this combination of ions.
Oxidation zone: The near-surface part of an ore deposit altered by oxygen-rich water and weathering. Azurite forms in this zone as copper minerals react with oxidizing fluids.
Azurite pigment: A blue pigment made by grinding azurite mineral into powder. Grinding converts the mineral into a historically important artists’ blue.
Lapis lazuli: A blue metamorphic rock valued as a gemstone and source of ultramarine pigment. It supplied a more costly blue pigment with a different mineral source and chemistry.
Monoclinic crystal system: A crystal system with three unequal axes, two meeting at oblique angles and one perpendicular to their plane. Azurite crystallizes in this system, shaping its characteristic crystal forms.
Supergene enrichment: The concentration of metals in an ore deposit through near-surface weathering and downward-moving fluids. The same weathering environment that forms azurite can redistribute copper within deposits.
Medieval painting: Painting produced in Europe during the Middle Ages, often using mineral pigments. Azurite was used for blue passages in medieval paintings and manuscripts.
Vivianite: A hydrated iron phosphate mineral that can appear blue or blue-green. Its similar colors can invite confusion, but its iron-phosphate composition differs.
Copper: A metallic chemical element with atomic number 29, known for high electrical and thermal conductivity. Copper supplies the metal ions that give azurite its composition and blue color.
Carbonic acid: A weak acid formed when carbon dioxide dissolves in water. Carbon-bearing water provides carbonate for azurite-forming reactions.

Linked from 8 pages