Template:POTD/2023-04-26
Azurite is a soft, deep-blue mineral produced by the weathering of copper-ore deposits. It is a basic carbonate with the chemical formula Cu3(CO3)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