岩緑青(いわろくしょう)iwarokushō
岩緑青、あるいは孔雀石(くじゃくいし)ともいう。天然の塩基性炭酸銅(えんきせいたんさんどう)(CuCO3・Cu(OH)2)。『続日本紀(しょくにほんぎ)』には金青とともに献上された記事がある。銅の表面に生ずる緑色の錆(さび)(組成は岩緑青とは異なる)を指す場合もある。
Malachite
A green crystallite stone composed of copper carbonate hydroxide Cu2CO3(OH)2. It forms banded stalactites where there is water. Similar to azurite, malachite often occurs together with the blue crystal. Ground to a fine powder, malachite is a prized pigment. Different degrees of pulverization produce various shades of green. The pigment was used to decorate offering boxes and other items in the Shōsō-in. The Continuation of Chronicles of Japan (Shoku nihongi) documents the donation of both malachite and azurite. The term can also apply to the green corrosion that forms on copper objects, though it differs from crystalline malachite. See also Kujakuishi.