other names: /
mineral class: Carbonates and nitrates
chemical formula: Cu2(OH)2| CO3
Chemical elements: Copper, oxygen, hydrogen, carbon
Similar minerals: Azurite, Chrysocolla
shine: Matt to diamond gloss
crystal structure: monoclinic
mass density: 3,8
magnetism: not magnetic
Mohs hardness: 4
stroke color: light green
transparency: translucent to opaque
use: Gemstone, color pigment
General information about malachite:
malachite describes a widely used mineral, which is assigned to the carbonates as well as the monoclinic crystal system and attracts attention by an intense glowing green. The coloring of malachite is due to the high content of copper and can vary from light green to emerald green and almost black. Often the malachite shows due to its shell-like structure delicate or pronounced bands and strokes, which may appear both light green and very dark.
The name of the mineral goes back to the ancient Greek words "malache" and "malakos", which mean "mallow" and "soft" and refer to the green appearance and the degree of hardness reminiscent of the mallow leaves. With a maximum Mohs hardness of 4, the malachite is one of the medium-hard rocks. It is characterized by complete cleavage, mussel breakage and develops needle-like and relatively small aggregates, occasionally also plates with strong encrustation as well as prismatic crystals. Malachite may have a glassy, diamond-like or silky sheen, depending on its condition and finish, and may be opaque as well as completely transparent. By the action of strong UV light and water, the malachite loses its bright color and can turn pale. Its attractive glass gloss is negatively influenced by higher temperatures. The contact with ammonia and hydrochloric acid causes a superficial dissolution.
Origin, occurrence and localities:
As secondary minerals, malachites form as a result of the weathering of rocks that have a high copper content. In the copper deposits, carbonate-rich water enters, which leads in the course of the reaction with iron ores to an oxidation. Excess water flows off and leads to oxidation processes at other points. As a result of this development, malachite is also detectable on the surface of stalactites or in sandstone. Often the green mineral is associated with copper, dolomite, limonite, calcite, azurite or cuprite.
Malachite is mined worldwide in a total of about 8,800 deposits, which are common on all continents. The most important countries with economically significant deposits include the British Isles, Sweden and Norway, Germany, Austria and Switzerland, as well as France, Italy, Hungary and Spain. Malachite is also being produced in large quantities in Japan and China, Mongolia, Afghanistan and Iraq, as well as in Central and South America, the United States and Australia.
Use of Malachite:
Malachite has been used as material for precious works of art and jewelery since antiquity. The Romans, Greeks and Egyptians as well as the people of ancient China used malachite to coat amulets, shellfish, statues, masks and grave goods. In powdered form Malachite was used as a green color pigment for murals and eye make-up. Malachite crushed to dust served as a basic material for the production of the so-called gold glue, which was used to solder goldsmith's work, right up to the Middle Ages. Today malachite is still used in jewelry making and craftsmanship for the manufacture of ornaments.