Malachite Oval Hammered Ring, Size 7

Malachite contains copper. Use polished pieces only, never breathe dust from raw or damaged stone, wash your hands after handling rough material, and never place it in drinking water. For a gem elixir, use the indirect method only, with the stone sealed in glass and not touching the water.

Malachite grows in the upper, weathered zones of copper deposits, where copper-rich water meets carbonate rock and slowly lays down band after band of green. People have worked it for at least six thousand years, from Egyptian mines in the Sinai to the Ural Mountains of Russia. Today most of it comes from the copper belt of the Democratic Republic of the Congo and Zambia.

Malachite is a copper carbonate hydroxide, a secondary mineral that forms where copper ore is exposed to oxygen and carbonated water near the surface. Its concentric bands and rosettes record successive layers of growth, each ring marking a shift in the fluid that deposited it. The name comes from the Greek word for mallow, after the green of the plant's leaves. Because it contains copper, its dust is toxic if inhaled or swallowed, so it is sold and handled in polished form.

• Egyptians mined malachite in the Sinai from around 4000 BCE and ground it into green eye paint, worn for beauty and as protection against the evil eye.
• In medieval European folklore, a piece of malachite was fastened to a child's cradle to keep harmful spirits away through the night.
• Russian tsars prized Ural malachite so highly that it clad the columns and vases of the Malachite Room in St. Petersburg's Winter Palace.