Malachite from the D.R. Congo
Smithsonian 4/2009; photo by S.W. Aber

GO 340 Gemstones & Gemology
ES 567 Gemstones of the World
Dr. Susan Ward Aber, Geologist & Gemologist
Emporia State University
Emporia, Kansas USA

academic.emporia.edu/abersusa/go340/malachit.htm

Malachite


Image taken from
John Betts, the weekly
mineral, November 11, 2000.
Malachite, a copper carbonate, Cu2CO3(OH)2, is found in varying shades of green. It is 3.5-4 on the hardness scale with a specific gravity of 3.25-4.10. It has cleavage and the fracture is splintery. Malachite falls within the monoclinic crystal system. It may be found as thin, translucent crystals, but more often seen as boytroidal, banded opaque masses. It has very strong pleochroism (colorless, yellow-green, dark green) and no fluorescence.


Image taken from
www.theimage.com/
gemstone/malachite/
mala1.html
,
The Image.

Image taken from
a former site at
The Image.
The coloring agent is copper, and malachite is formed from copper-containing solutions in or near copper ore deposits (Schumann, 1997, p. 176). This oxidation zone of copper deposits also creates azurite, limonite, and chalcopyrite, which are all found in association with malachite. The most important geographic locations are in Zaire, as well as the Ural Mountains, where massive blocks were mined and became wall paneling and table tops for Russian czars. Malachite also comes from Australia, Chilie, Namibia, Zimbabwe, and Arizona, Nevada, and California, in the US.
Malachite pseudomorph
after azurite crystals.
Image taken from
John Betts Minerals.

Malachite and azurite.
Image taken from
The Image.
Eilat stone is intergrown malachite, turquoise, and chrysocolla, whereas azure-malachite is malachite and azurite intergrowths. In addition to jewelry and artistic decorations, malachite was mixed with ground ants to create eye make-up in Egyptian times. It has been used as a green paint pigment too. It is less valuable than turquoise, jade, and lapis.
.

References

Return to the Syllabus or choose another gemstone below.

Alexan drite Amber Amethyst Chalcedony Diamond Emerald
Garnet Jade Malachite Opal Pearl Peridot
Ruby Sapphire Tanzanite Topaz Tourmaline Turquoise

This page originates from the Earth Science department for the use and benefit of students enrolled at Emporia State University. For more information contact the course instructor, S. W. Aber, e-mail: esu.abersusie@gmail.com Thanks for visiting! Webpage created: November 15, 2000; last update: September 16, 2012.

Copyright 1999-2012 Susan Ward Aber. All rights reserved.