Brauns, R. (Reinhard), 1861-1937, Spencer, Leonard James, 1870- · Esslingen a. N. : J. F. Schreiber · leaf 194
ring in nature, only one is of any importance as an ore; this is wolframite, a tungstate of iron and manganese (Fe,Mn)W04. Scheelite, a tungstate of calcium CaW04, is of importance as a mineral, but the others (stolzite PbW04 and hiibnerite MnW04) are of cpiite rare occurrence. Scheelite, a mineral… … is thus tetragonal with pyramidal-hemihedrism, and it affords the best example of this type of symmetry. The crystals are usually yellow of various shades (plate 39, figs. 1 — 5), but sometimes grey or white (fig. 6); they are transparent to translucent, and may be bright or dull and rough. The…
Mineralogy
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