蓝铜矿又名石青，是一种含铜的矿物，深蓝色或浅蓝色，有玻璃光泽，其化学成分为 Cu₃(CO₃)₂(OH)₂，单斜晶系，晶体呈矩柱状或板状，集合体为簇状、放射状、钟乳状或粒状，硬度为3.5-4，比重为3.77-3.89。

蓝铜矿在各种语言中都是用蓝色来命名，希腊语为kuanos，拉丁语为caeruleum，英语为azurite，则是来源于阿拉伯语中的蓝色lazhward。

蓝铜矿常与孔雀石共生，数量多时可以作为铜矿，提炼铜，经研磨成粉末可以做蓝色颜料，是中国画中常用的一种颜料，根据其研磨的细腻程度，颜色略有差异，在中国画中分为头青、二青等。大而鲜艳的晶体也可作为宝石或观赏石，但因其质地软，易风化，不易保存。

Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France. The mineral, a carbonate, has been known since ancient times, and was mentioned in Pliny the Elder's Natural History under the Greek name kuanos (κυανός: "deep blue," root of English cyan) and the Latin name caeruleum. The blue of azurite is exceptionally deep and clear, and for that reason the mineral has tended to be associated since antiquity with the deep blue color of low-humidity desert and winter skies. The modern English name of the mineral reflects this association, since both azurite and azure are derived via Arabic from the Persian lazhward (لاژورد), an area known for its deposits of another deep blue stone, lapis lazuli ("stone of azure").