MALACHITE & AZURITE
Malachite & azurite are attractive, richly colored
copper hydroxy-carbonate minerals. Malachite has a nice green
color - its formula is Cu2CO3(OH)2. Azurite
has a dark, rich blue color - its formula, Cu3(CO3)2(OH)2,
is very close to malachite. The blue color of azurite is from Cu+,
while the green color of malachite is from Cu+2. Azurite &
malachite almost invariably occur together, and are telling indicators of
copper in the field, even in very small quantities. Blue azurite tends to
crystallize first, and can convert to green malachite. Some
azurite-malachite specimens are solid enough to be cut and polished as
semi-precious stone.
Malachite & Azurite (7.5 cm across)
Botryoidal malachite (7.7 cm across) from Katanga Province, southern Zaire
("D.R. Congo").
Botryoidal malachite (3.9 cm across) from Milpillas, Sonora, Mexico.
Azurite
Azurite
from Shilu, Guangdong Province, China.
Azurite and malachite (above & below) acting as cement minerals in a
breccia. From the Morenci Mine in Arizona, USA.