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RHODONITE , a member of the See also: pyroxene See also: group of minerals, consisting of manganese metasilicate, MnSiO3, and crystallizing in the anorthic See also: system
.
It commonly occurs as cleavable to compact masses with a See also: rose-red colour; hence the name, from the See also: Greek 1 YSov (a rose)
.
Crystals often have a thick See also: tabular habit; there are perfect cleavages parallel to the prism faces with an angle of 87° 312'
.
The hardness is 52-627 and the specific gravity 3.4-3.68
.
The manganese is often partly replaced by iron and calcium, which may sometimes be See also: present in considerable amounts; a greyish-See also: brown variety containing as much as 20% of calcium
See also: oxide is called " bustamite " ; " fowlerite " is a zinciferous variety containing 7% of See also: zinc oxide
.
Rhodonite is a See also: mineral liable to alteration, with the formation of manganese carbonate, hydrous silicate or oxides
.
The compact material, which is cut and polished for ornamental purposes, is often marked in a striking manner by See also: veins and patches of these black alteration products
.
At Syedelnikova, near See also: Ekaterinburg in the Urals, compact material of a See also: good colour occurs in a See also: clay-slate and is extensively quarried: boulders of similar material found at Cummington ,in Massachusetts (" cummingtonite f7) have also been worked as an ornamental See also: stone
.
In the iron and manganese mines at Pajsberg near Filipstadt and Langban in Vermland, Sweden, small brilliant and translucent crystals (" pajsbergite ") and cleavage masses occur
.
Fowlerite occurs as large, rough crystals, somewhat resembling
See also: pink See also: felspar, with See also: franklinite and zinc ores in granular See also: limestone at See also: Franklin See also: Furnace in New See also: Jersey
.
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