Nambulite Value, Price, and Jewelry Information

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.