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Formula: Bi2Te2Se
Selenide, bismuth- and
tellurium- bearing mineral,
tetradymite group
Crystal System: Trigonal
Specific gravity: 8.08 calculated
Hardness: 1½
Streak: Light steel grey
Colour: Silver to tin-white
Common impurities: Fe,S
Environments
Kawazlite is of hydrothermal origin in
sulphide/arsenide/selenide veins
(Mindat).
It has the curious property of being a topological insulator, and one that is cleaner than synthetic samples.
Topological insulators are exotic materials that conduct electricity only along their surfaces, and kawazulite
is the first naturally occurring mineral shown to have this property. It could have important applications in the
development of quantum computing
(Nature doi:10.1038/nature.2013.12569).
Localities
The Sue-Dianne deposit, Diane Lake, Mazenod Lake District, Northwest Territories, Canada, is a small
uranium-copper deposit. A breccia pipe
several hundred metres in diameter, defined by tourmaline veinlets, cuts
dacitic ignimbrites. These
intensely hematised host rocks are occasionally cut by small veinlets of
hematite-pitchblende that also host the
bismuth-copper-lead-sulphur-selenium-tellurium
mineralisation. Primary and
secondary hematite can be
distinguished in the veinlets; primary
hematite has a platy habit, whereas
secondary hematite,
produced by the oxidation of magnetite, is present as equidimensional grains with
relict magnetite cores. The pipe exhibits extensive superficial
copper-rich oxidation products.
The Canadian kawazulite occurs in trace amounts, intimately associated with
selenium-bearing covellite. The
anhedral
grains do not exceed 25 microns in diameter. Kawazulite is also found as submicron inclusions within the
covellite; it has either exsolved from
covellite or coprecipitated with it.
The first of the minerals to be deposited at Mazenod Lake was magnetite,
some
primary hematite
followed,
before the main period of hematite formation and
uranium-copper-bismuth-lead-sulphur-selenium-tellurium
mineralisation
(CM.19.341-348).
Other minerals associated with kawazulite include
tellurobismuthite,
uraninite, hematite and
yarrowite
(HOM).
At the Suttsu mine, Shiribeshi Subprefecture, Hokkaidō Prefecture, Japan, kawazulite is of hydrothermal origin,
ocurring in a quartz vein associated with
selenium-bearing bismuthinite,
selenium-bearing pavonite,
cassiterite, chalcopyrite
and
pyrite
(HOM).
At the type locality, the Kawazu mine, Rendaiji, Shimoda City, Shizuoka Prefecture, Japan, kawazulite is of
hydrothermal origin, occurring in a quartz vein in the
tellurium deposit as very thin foils up to 4 mm across, with a maximum
thickness
of 50 microns. Associated minerals include selen-tellurium
(HOM, Mindat).
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