Pair of sliced Malachite and Azurite

Malachite and azurite nodules.

This specimen features a showy and excellent complementary pair of sliced and polished malachite and azurite nodules from an uncommon locality for the species—Inyo County, California. Both nodules exhibit an azurite rind. The azurite nodule displays beautiful, multi-hued blue banding, reminiscent of the well-known Bisbee nodules. The malachite-rich side of the nodule has a more unusual, radial, bladed appearance.

Malachite

• Formula: Cu₂(CO₃)(OH)₂
• System: Monoclinic
• Colour: Bright green, with ...
• Hardness: 3½ - 4
• Streak: Light green

Malachite is a bright green, very common secondary copper mineral with a widely variable habit. It is typically found as crystalline aggregates or crusts, often banded in appearance, similar to agates. It also frequently occurs as botryoidal clusters of radiating crystals and as mammillary aggregates.

Azurite

• Formula: Cu₃(CO₃)₂(OH)₂
• System: Monoclinic
• Colour: Azure blue, blue, light ...
• Lustre: Vitreous
• Hardness: 3½ - 4

Azurite is a secondary copper mineral commonly found in the oxidized zones of copper-bearing ore deposits. It is known for its striking azure blue color and vitreous luster.