penwithite

[After Pen with, West Cornwall; suff. -ite ( Min.).] Min.: An amorphous mineral, found in a ociation with quartz and rhodochroisite. Hardne , 3.5; specific gravity, 249; luster, vitreous; color, dark reddish-brown; transparent; fracture, conchoidal. An analysis yielded: Silica, 36:40; protoxide of manganese, 37-62; protoxide of iron, 2.52; water, 21.80; sesquioxide of uranium, 0.30=98.64. Suggested formula, MnSiO3+2aq. pen-wom-an, s. [Eng. pen (2), and woman.] A female writer; an authore . ( Richardson: Clari a Harlowe, i. 329.)