Its rarity and attractiveness are the reason for the typically high prices one would expect to pay for a fine specimen. Color is typically various shades of green, rarely black. Luster is resinous. Crystals are transparent to opaque. Cleavage is none.
Fracture is conchoidal to uneven.
Hardness is 3 to 3.5. Streak is green. Associated Minerals are descloizite , malachite and other secondary ore minerals. Best Field Indicators are color, crystal habit, locallities and density.