Azurite is a soft, deep-blue mineral produced by the
weathering of
copper-ore deposits. It is a basic
carbonate with the chemical formula Cu
3(CO
3)
2(OH)
2, and has been known since ancient times, being mentioned in
Pliny the Elder's
Natural History under the Greek name
kuanos and the Latin name
caeruleum. These azurite crystals, covering a 4.0 cm × 3.0 cm × 2.0 cm (1.57 in × 1.18 in × 0.79 in)
matrix with a little
malachite, were found in a
lode in
La Sal, Utah. This photograph was
focus-stacked from 55 separate images.
Photograph credit: Ivar Leidus