Chemical composition -- Copper oxide.
Color -- Intense red, brownish red, or purplish red.
Optics -- R.I 2.85.
Durability -- Hardness 3.5-4. Brittle.
Crystal structure -- Cubic.
Specific Gravity -- 6.0-6.1 (very dense).
Sources -- Tiny crystals of cuprite are found worldwide, but the only source of large stones (yielding finished stones up to 300 carats) is Onganja, Namibia.
The rarity, deep red color, and high R.I. make cuprite a very desirable collector stone, found in only a few collections.