46.—Manganese Spar.
Occurs in masses; glassy lustre; color flesh or rose-red; becomes black on exposure; tough; melted with borax gives a violet-blue color; gravity 3.5.
Value.—Used in glazing stone-ware.
Localities.—Found in granite regions, often with iron-ore. Blue Hill Bay, Me.; Cummington, Warwick and Plainfield, Mass.; Irasburg and Coventry, Vt.; Winchester, and Hinsdale, N. H.; Cumberland, R. I.; Franklin and Hamburg, N. J.