2.7" Cerussite Crystals on Sparkling Botryoidal Malachite - Congo

Cerussite is a lead-carbonate mineral with the chemical formula PbCO3, and is an important ore of lead. It is a common weathering product of galena, explaining why it is typically extracted from oxidized zones of lead ore deposits. It can form into a variety of different structures, sometimes in fibrous patterns and other times in granular aggregations, though it generally forms vitreous pseudo-hexagonal crystals. Its colors vary depending on composition and structure: it is most commonly colorless, white, grey and green-tinted.

Malachite is an intense green copper-based mineral that can be found in a wide variety of forms. Malachite can grow in botryoidal masses, stalactitic formations, and reniform formations, typically as a tight cluster of fanning fibrous needles that make up a seemingly solid mass. As layers continue to stack during formation, banded patterns can sometimes begin to take shape, explaining the rings in all shades of green seen on most polished malachite specimens.

Malachite results from the weathering of other copper ores, and is very often found associated with other copper-based minerals such as azurite and chrysocolla. It can be found in copper deposits around the world, but the Democratic Republic of the Congo is the primary source for polished malachite and mineral specimens.

Malachite has been prized since ancient times, first as a utilitarian copper ore, then as an ornamental stone. Due to its value as a decorative stone, it is rarely mined as a copper ore anymore.