This vivid green gem gets its color from copper. Invariably associated with copper ore deposits, malachite ranks as a minor copper ore, with 58% copper content. Its recovery generally occurs, at least on a large scale, as a sidelight of copper mining.
Technically, malachite is a “secondary mineral,” which means it’s created by a chemical reaction between minerals that have already formed, rather than by a simple one-step process. Malachite may form when water containing carbon dioxide or dissolved carbonate minerals interacts with preexisting copper-containing rocks or when solutions containing dissolved copper minerals interact with carbonate rocks.
Malachite’s characteristic swirling and concentric band patterns are a result of this formation process. These bands reflect the waxing and waning of the solutions necessary for formation and the changes in their chemical content. Most commonly, the stone occurs in massive form as a microcrystalline aggregate, in lumps, or as crust on other rocks.
History and Uses
Malachite may have been mined in Egypt as early as 4,000 BCE. Not only was it used as a gemstone and ornamental material, the stone was ground into pigments for painting and cosmetics. Not until the Industrial Revolution were synthetic pigments created that could rival its color. Restoration experts still use malachite pigment formulas for authenticity when conserving old paintings. Unfortunately, this beauty can also be hazardous. The copper content of the dust released from grinding malachite makes it toxic to breathe.
Today, workers involved in the mining and fashioning of the stone should wear protective respiratory gear. Keeping the rough wet also keeps dust to a minimum.
Many cultures throughout history have prized malachite. The green stone has been used in protective amulets since ancient times. Perhaps its greatest appreciators were the Russian royals of the 19th century. They had dining sets, huge sculptures, vases, and even paneling made from it. You can take a virtual tour of the celebrated “Malachite Room” in the Winter Palace at the Hermitage Museum in St. Petersburg, Russia.
The Victorians were great admirers of opaque jewelry stones, and malachite was one of their favorites. Jewelers often used this material in small carvings, beads, and cabochons set in silver and, occasionally, gold.
Malachite jewelry. Photo © Joel E. Arem, PhD, FGA. Used with permission.
Lapidary artists use this stone extensively to make cabochons, beads, boxes, inlays, and carvings of all kinds. With great care, skilled artists can turn malachite on a lathe to create goblets and candlesticks.
Facetable crystals would be microscopic in size, since larger crystals are too opaque to let light through. A faceted malachite gem larger than ½ carat would be opaque.
Malachite can appeal to the gem lover as well as anyone interested in nature’s wonders. Mineral and gemstone collectors compete to acquire prime specimens in some of the stone’s rarer habits. Some of the most desired forms are: botryoidal masses, stalactites or slices cut from them, and pieces with splayed-out clusters of needle-like (acicular) crystals showing a velvety chatoyancy. Fibrous aggregates (packed masses of crystals) can also take a high polish.
Malachites sometimes form in combination with other copper-bearing minerals. Blue-green chrysocolla, dark blue azurite, or brick-red cuprite can create rocks of unsurpassed beauty when combined with malachite’s forest green.
Although scientists have synthesized malachite for research purposes, this material isn’t found commercially. The synthetic material costs far more than the abundant, natural mineral.
Malachite rarely receives any treatments. However, lower quality, less compact pieces may be stabilized with plastic resins or given a surface polish with wax.
The majority of malachite rough comes from the Democratic Republic of the Congo (formerly Zaire), Namibia, Russia and the American Southwest.
- Australia: N.S.W., Broken Hill.
- Democratic Republic of the Congo: banded material, also stalactitic, most familiar on marketplace.
- Namibia: Tsumeb, magnificent large crystals.
- Russia: Mednorudyansk, immense masses, some up to 50 tons! Much of it good for cutting. Also from mine at Nizhne-Tagilsk.
- United States: Arizona, at Bisbee and Gila, other localities; New Mexico; Tennessee; Utah.
Malachite, Democratic Republic of the Congo (~ 4 inches high). Photo © Joel E. Arem, PhD, FGA. Used with permission.
Cabochons and carvings from banded material can be virtually any size. Stalactites can occur up to several feet in length. Slabs have even been used as paneling in palaces. Facetable crystals are virtually nonexistent. Any cut gem would be very small, less than 2 carats, but massive aggregates can weigh tons.
Malachite is soft, somewhat brittle, and sensitive to both heat and acids. It requires gentle care. Mechanical cleaning methods, such as ultrasonic or steam cleaning, aren’t recommended. Use in rings, bracelets, or other jewelry that may receive rough treatment or constant wear isn’t advisable. Use in earrings, brooches, pendants, and tie pins should pose no special problems.
Don’t use any acidic cleaners on malachite jewelry. Although faceters should take precautions when cutting malachites, wearing finished jewelry pieces should pose no health hazards.
Consult our gemstone jewelry care guide for recommended cleaning methods.