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Formula: Ca2Mn2+2B4O7(OH)6
Tetraborate, manganese-bearing
mineral, forms a series with fedorovskite
Crystal system: Orthorhombic
Luminescence: Not fluorescent
Specific gravity: 2.935 measured, 2.939 calculated, 2.92 calculated for the empirical formula for roweite
from the Fuka mine
Hardness: 4½ to 5
Colour: Light brown; colourless in transmitted light
Solubility: Perfectly soluble in dilute hydrochloric acid
Environments
Sedimentary environments
Metamorphic environments
Localities
At the Shijiangshan mine, Hexigten Banner, Chifeng City, Inner Mongolia, China, aggregates of between laminar and
tabular roweite crystals of great size and quality have been found. They are on matrix with small
andradite crystals with a light creamy colour, and partially coated by
groups of white olshanskyite crystals
(Mindat photo).
Roweite from the Shijiangshan Mine -
Image
At the Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan, roweite was discovered as
aggregates of several fine crystals in a borate mineral assemblage block.
The block mainly consists of shimazakiite in crystalline
limestone close to
gehlenite–spurrite
skarns. These skarns were
formed as pyrometasomatic products of limestone. Several
roweites occur as an aggregate of radial column crystals and a granular crystal from 0.1 to 0.8 mm across in
an uralborite crystal, which is one of the minerals in the block
consisting of uralborite and
frolovite without
shimazakiite in the crystalline
limestone. Roweite seems to replace
uralborite. The other associated minerals are
bultfonteinite, calcite and
fluorite.
Roweite is reddish brown or dark brown with a vitreous
lustre in hand specimens. In thin section, the mineral is pale yellowish brown to dark brown and transparent
(Journal of Mineralogical and Petrological Sciences 110.29–34).
At the type locality, the Franklin Mine, Franklin, Sussex County, New Jersey, USA, roweite was found in a
narrow veinlet in very close association, and in places intergrown, with
clinochrysotile, but with no associated
thomsonite (as had been reported earlier, presumably erroneously). The
wall-forming minerals of the roweite veinlet are franklinite,
zincite and willemite; inclusions
of these minerals are sparse in some roweite crystals. The most abundant included material, however, is
clinochrysotile with which roweite may occur as parallel or,
less commonly, as complex intergrowths. Roweite replaces anhedral masses of
calcite which are in optical continuity throughout a roweite crystal
and which show effects of solution. Much of the roweite, however, is essentially free from inclusions of any
kind
(AM 59.66-70).
Roweite from the Franklin Mine -
Image
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