Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate, LiAl(SiO3)2, and is a source of lithium. It
occurs as colorless to yellowish, purplish, or lilac kunzite (see below),
yellowish-green or emerald-green hiddenite, prismatic crystals, often of great
size.
Detailed d
Discovery and occurrence
Economic importance
Gemstone varieties
Hiddenite
Kunzite
Detailed d
Single crystals of 14.3 m (47 ft) in size
are reported from the Black Hills of South Dakota, United States.[5][6]
The normal low-temperature form α-spodumene is in
the monoclinic system whereas the
high-temperature β-spodumene crystallizes in the tetragonal system. The normal
α-spodumene converts to β-spodumene at temperatures above 900 °C.[4] Crystals are
typically heavily striated parallel to the principal axis. Crystal faces are
often etched and pitted with triangular markings.
Discovery and occurrence
Spodumene was first described in 1800 for an
occurrence in the type locality in Utö, Södermanland, Sweden. It was discovered by Brazilian naturalist Jose Bonifacio de
Andrada e Silva. The name is derived from the Greek spodumenos (σποδυμενος),
meaning "burnt to ashes," owing to the opaque, ash-grey appearance of
material refined for use in industry.[1]
Spodumene occurs in lithium-rich granite pegmatites and aplites. Associated minerals include: quartz, albite, petalite, eucryptite, lepidolite and beryl.[2]
Transparent material has long been used as a gemstone with varieties
kunzite and hiddenite noted for their strong pleochroism. Source localities include Afghanistan, Australia, Brazil, Madagascar, Pakistan, Québec in Canada and North Carolina, California in the US.
Economic importance
Spodumene is an important source of lithium for use
in ceramics, mobile phone and automotive batteries, medicine, Pyroceram and
as a fluxing agent. Lithium is extracted from spodumene by fusing in acid.
World production of lithium via spodumene is around
80,000 metric tonnes per annum, primarily from the Greenbushes pegmatite of Western Australia and from some Chinese and Chilean sources. The Talison
mine in Greenbushes,
Western Australia has
an estimated reserve of 13 million tonnes.[7]
Some[who?] think that spodumene
will become a less important source of lithium due to the emergence of alkaline brine lake sources
in Chile, China and Argentina, which produce lithium chloride directly. Lithium
chloride is converted to lithium carbonate and lithium hydroxide by reaction with sodium carbonate and calcium hydroxide respectively.
However, pegmatite-based projects benefit from being quicker to move into
production than brines, which can take 18 months to 3 years, depending on
evaporation rates. With pegmatites, once a mill is built, the production of
lithium carbonate takes only a matter of days.
Another key advantage that spodumene has over its
more popular brine rivals is the purity of the lithium carbonate it can
produce. While all product used by the battery industry has to be at least
99.5% lithium carbonate, the makeup of the remaining 0.5% is important; higher
amounts of iron, magnesium or other deleterious materials make for a less
attractive product.
Gemstone varieties
Hiddenite
Hiddenite is a pale emerald
green gem variety first reported from Alexander County,
North Carolina, US. It was named in honor of William Earl Hidden
(16 February 1853 - 12 June 1918), mining engineer, mineral collector, and
mineral dealer.
This emerald green variety of spodumene is colored
by chromium, just like emeralds. Not all green spodumene is colored with
chromium, which tend to have a lighter color, and therefore are not true
hiddenite.
Kunzite
Kunzite is a pink to lilac
colored gemstone, a variety of spodumene
with the color coming from minor to trace amounts of manganese. Some (but not all)
kunzite used for gemstones has been heated to enhance its color. It is also
frequently irradiated to enhance the
color.
Kunzite was discovered in 1902, and was named after George Frederick Kunz, Tiffany & Co's chief jeweler at
the time, and a noted mineralogist. It has been found in Brazil, US, Canada, CIS, Mexico, Sweden, Western Australia, Afghanistan and Pakistan.
One notable example of kunzite used in jewellery is
in the Russian Palmette tiara and necklace worn by the Duchess of Gloucester.
PRICE
$9/KG OR $4.09/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
Comments
Post a Comment