- Chemistry: Cu3PO4(OH)3, Copper Phosphate Hydroxide.
- Class: Phosphates
- Uses: mineral specimens.
Cornetite is a rare secondary copper mineral that is noted for its deep
blue, green-blue to green color. It is found in highly weathered, oxidation
zones of copper sulfide ore bodies. It has a good deep color, nice crystal
forms and an attractive sparkle, all the ingredients for a popular collection
- Color is dark blue, green-blue to green.
- Luster is vitreous.
- Transparency: Specimens are translucent.
- Crystal System: is orthorhombic; 2/m2/m2/m
- Crystal Habits include crystals that are short, rounded, nearly
diamond-shaped prisms that are terminated by a dome with trapezohedral
faces, also as tiny crystalline druzes, fibrous masses and crusts.
- Cleavage is absent.
- Fracture is uneven.
- Hardness is 4.5
- Specific Gravity is approximately 4.1 (above average for translucent
- Streak is blue.
- Associated Minerals are
and other secondary copper ore minerals.
- Notable Occurrences include Shaba, Congo; Bwana Mkubwa, Zambia
and Empire Nevada Mine, Yerington,Nevada.
- Best Field Indicators are color, streak, crystal habits, associations