Vanadium-bearing minerals from the Komatsu mine, Saitama prefecture

Abstract

Ansermetite and franciscanite are found in fissures of manganese ore from the Komatsu mine, Saitama Prefecture. Ansermetite occurs as orange-red blades, and franciscanite as a black veinlet. Analyses by EPMA gave the empirical formula, Mn_1.04V_1.98O₆/3.17H₂O for ansermetite, Mn_6.2(V_0.5W_0.02( )_0.48)Si_1.8[O_10.2(OH)_4.5] for franciscanite. Lattice parameters obtained with a XRD method are; a=1.316, b=1.011, c=0.698(nm), β=111.6deg., and a=0.8150, c=0.4804(nm), respectively.