[mang-guh-nahyt] 
| 1. | a gray to black mineral, hydrous manganese oxide, MnO(OH); gray manganese ore. |
| 2. | Chemistry. any of a series of salts containing tetravalent manganese and derived from either of two acids, H4MnO4 or H2MnO3. |
| man·ga·nite (māng'gə-nīt') n. A steel-gray to black mineral, MnO(OH), found in North America and Europe; manganese oxide. |
manganite
an ore mineral of manganese, basic manganese oxide [MnO(OH)] that forms dark gray to black crystal bundles or fibrous masses. Important deposits exist at Ilfeld, Ilmenau, Siegen, and Horhausen, Ger.; the Lauron and Aure valleys, in France; St. Just, Cornwall, Eng.; and Michigan and California, U.S. As a manganese ore it ranks after pyrolusite and romanechite, to which it readily alters. For detailed physical properties, see oxide mineral (table)
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gəˌnaɪt