Nambulite Value, Price, and Jewelry Information
The color of Namibian nambulite is a striking orange-red, very intense, and not really like any other gem I have seen. Cut stones would be both extremely rare and quite magnificent, perhaps bearing some similarities to rhodonite.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Crystallography||Triclinic. Crystals prismatic, ﬂattened, and wedge shaped.|
|Colors||Reddish brown, orange-brown, orange.|
|Cleavage||Perfect 1 direction, distinct 1 direction|
|Stone Sizes||Gems up to about 10 carats could potentially be cut from Namibian crystals.|
|Absorption Spectrum||Not diagnostic.|
|Optics||a = 1.707; β = 1.710; γ = 1.730. Biaxial (+), 2V= 30°.|
Optics: a = 1.707; β=1.710; γ=1.730.
Biaxial (+), 2V= 30°.
Occurrence: Nambulite is a rare mineral reported in crystals up to 8 mm long at the Tunakozawa Mine, Northeast Japan. These crystals are found in veins cutting manganese oxide ores. Much larger crystals, up to approximately 3 cm across, have more recently been found in Namibia, at the Kombat Mine, near Tsumeb. I have seen a completely transparent crystal in a private collection that would yield about 20-25 carats of flawless faceted gems, the largest of these perhaps 10 carats in weight.
Comments: The color of Namibian nambulite is a striking orange-red, very intense, and not really like any other gem I have seen. Cut stones would be both extremely rare and quite magnificent, perhaps bearing some similarities to rhodonite.
Name: After Professor Matsuo Nambu of Tohoku University, Japan, for his studies of manganese minerals.