Chrysocolla (/ˌkrɪsəˈkɒlə/ KRIS-ə-KOL-ə) is a hydrous copper phyllosilicate mineral and mineraloid with the formula Cu2 – xAlx(H2Si2O5)(OH)4⋅nH2O (x < 1)[1] or (Cu, Al)2H2Si2O5(OH)4⋅nH2O).

[4] The structure of the mineral has been questioned, as a 2006 spectrographic study suggest material identified as chrysocolla may be a mixture of the copper hydroxide spertiniite and chalcedony.

It is of secondary origin and forms in the oxidation zones of copper ore bodies.

A 2006 study has produced evidence that chrysocolla may be a microscopic mixture of the copper hydroxide mineral spertiniite, amorphous silica and water.

[6][1] Due to being somewhat more common than turquoise, its wide availability, and vivid, beautiful blue and blue-green colors, chrysocolla has been popular for use as a gemstone for carvings and ornamental use since antiquity.