McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams

Home » Minerals » Spodumene

Spodumene


An important source of high-purity lithium and a gemstone with collector appeal



What is Spodumene?



Spodumene is a pyroxene mineral that is found, almost exclusively, in granite pegmatites. It has a chemical composition of LiAlSi2O6 but small amounts of sodium sometimes substitute for lithium. Spodumene is typically found in lithium-rich pegmatites in association with other lithium minerals such as lepidolite, eucryptite and petalite. In the historical literature the mineral is often referred to as "triphane."


Enormous Crystals



Spodumene often occurs in extremely large crystals. One of the earliest accounts of large spodumene crystals is from the Etta Mines, Black Hills, Pennington County, South Dakota. The United States Geological Survey, Bulletin 610 reports:
"The crystals are often of enormous size. In the Etta Mine, where they are best exposed both in the open cut and tunnel, they frequently attain a diameter of 3 to 4 feet and a length of 30 feet. The largest "log" so far found was 42 feet long and 5 feet 4 inches in maximum diameter. This one log alone would yield 90 tons of spodumene." [1]

giant spodumene crystals - Etta Mines
Molds of giant spodumene crystals at the Etta Mines, Black Hills, Pennington County, South Dakota. Note miner at right center for scale. USGS photo. [1]


Uses of Spodumene



Spodumene once served as the most important ore of lithium metal. Although it remains an important source of lithium, today most of the world's lithium is produced from subsurface brines in Chile, Argentina, and China. These sources of lithium have lower production costs and are suitable for most uses. However, when lithium of highest purity is needed, spodumene is the source that is used.


Physical Properties of Spodumene

Chemical Classification silicate
Color White, gray, yellow, green, blue, lilac, pink, brown. Sometimes pleochroic
Streak White, colorless.
Luster Vitreous, pearly.
Diaphaneity transparent to translucent
Cleavage perfect in two directions with parting
Mohs Hardness 6.5 to 7
Specific Gravity 3.1 to 3.3
Diagnostic Properties Prismatic crystals with strong striations parallel to their principal axis. Perfect cleavage.
Chemical Composition LiAl(SiO3)2
Crystal System monoclinic (low temperature) tetragonal (high temperature)
Uses


Spodumene as a Gemstone



Spodumene sometimes occurs in transparent crystals in pastel shades of pink, green and yellow. These have been cut into gemstones that are prized by collectors. However, their use in jewelry is limited to pieces that will be subject to limited abuse because of spodumene's perfect cleavage.

Kunzite



Pink to lilac specimens of gem-quality spodumene are highly prized and known as "kunzite". The color of these specimens is attributed to the presence of manganese as a chromophore. Kunzite is the most commonly encountered spodumene gem.

Many specimens of kunzite are strongly pleochroic with the deepest color observed when the gem is viewed down the principal axis. To take full advantage of its phenomenon, gemstones are cut with the table perpendicular to the principal axis to yield stones of the deepest color.

Some kunzite will develop a richer color when heated or irradiated. These procedures have been applied to some stones that enter the marketplace. Some specimens of kunzite will fade over time when exposed to direct sunlight. Valuable stones should be stored away from direct light and, to be conservative, in a closed container.

Hiddenite



Emerald green spodumene is known as "Hiddenite." Its vivid green color is very similar to emerald and is attributed to the presence of chromium as a chromophore. It is the rarest gem variety of spodumene. It was first found near the town of Stony Point, North Carolina, which changed its name to "Hiddenite" after the popular gemstone that attracted people to the area.

Other Colors



Yellow and clear specimens of spodumene have also been cut into gems; however, variety names for spodumene gems have only been given to Kunzite and Hiddenite.


Demand for Spodumene



The demand for spodumene is dependent upon the use of lithium in manufacturing. In the past, most lithium compounds and minerals were used to produce ceramics, glass, aluminum alloys and high-temperature grease. However, an exploding demand for rechargeable batteries to power cell phones, tablet computers, cameras, music players, GPS units and other portable electronic devices is driving the demand for high-purity lithium - and that drives the demand for spodumene.

Lithium batteries have a much higher charge-to-weight ratio and power-to-weight ratio than lead/acid and zinc carbon cells. This makes lithium the battery material of choice.

Lithium produced from spodumene has fewer contaminants than lithium produced from brines. These contaminants can interfere with battery performance and make spodumene the preferred choice for battery lithium. A new battery technology could displace the use of lithium; however, most new battery technologies have been lithium-based.


Contributor:



Find it on Geology.com




More from Geology.com


Fluorescent Minerals
Fluorescent Minerals glow with spectacular colors under ultraviolet light.
rocks
Rock Gallery: Photos of igneous, sedimentary and metamorphic rocks with descriptions.
Organic Gems
Organic Gems are gems formed from or by plants or animals. They might also be fossils.
caldera
Calderas are enormous volcanic craters formed by some of Earth\'s largest eruptions.
Iris Agate
Iris Agate produces surprising colors when light passes through its thin bands.
volcanic explosivity index
Volcanic Explosivity: Learn about some of the most explosive volcanic eruptions.
Oil and Gas
Oil and Gas: Articles about oil and natural gas in the US and around the world.
shale gas
Shale Gas is natural gas trapped within shale. It is a growing source of US supply.


spodumene
Translucent to transparent spodumene with an attractive pink, yellow or green color is sometimes faceted, cut en cabochon or used to make tumbled stones. Its perfect cleavage limits its use to jewelry that will not be subject to rough wear or handling. Spodumene is primarily a "collector's gemstone." The larger pieces of spodumene in this image are about one inch long.




spodumene
Pink gem-quality spodumene (kunzite) from the Konar Valley, Konar, Afghanistan. Creative commons image by Didier Descouens.


spodumene
An ore-grade spodumene crystal section showing cleavage and typical striations. Photograph by Andrew Silver, USGS, BYU Collection.


uses of lithium
Lithium has many diverse uses. This chart shows estimated global uses of lithium by end product. It is mainly used in manufacturing ceramics, specialty glass, rechargeable batteries, high-temperature grease, continuous castings, polymers, aluminum alloys and pharmaceuticals. USGS data. [2]

lithium battery
One of the primary uses of spodumene is in the production of high-purity lithium for use in lithium-ion batteries. The popularity of small electronic devices such as cell phones, portable computers and cameras is driving the demand for spodumene. Photo © Anton Snarikov, iStockphoto.


lithium pills Did You Know? Lithium is an active ingredient in some medications. Salts of lithium are used in medication for bipolar disorder. The lithium contributes to a "mood-stabilizing" effect. One product has been named "Lithium." Image © Paige Foster, iStockphoto.


Spodumene Information
[1] Mineralogic Notes, Series 3: Waldemar Schaller, Gigantic Crystals of Spodumene, United States Geological Survey, Bulletin 610, 1916.

[2] Lithium: Brian Jaskula, United States Geological Survey, Mineral Commodity Summary, January 2012.

[3] Lithium: Brian Jaskula, United States Geological Survey, Minerals Yearbook, December, 2011.



Mineral Information
 Andalusite
 Anhydrite
 Apatite
 Arsenopyrite
 Augite
 Azurite

 Barite
 Bauxite
 Beryl
 Biotite
 Bornite

 Calcite
 Cassiterite
 Chalcocite
 Chalcopyrite
 Chlorite
 Chromite
 Chrysoberyl
 Cinnabar
 Clinozoisite
 Copper
 Cordierite
 Corundum
 Cuprite
 Diamond
 Diopside
 Dolomite

 Enstatite
 Epidote

 Fluorite

 Galena
 Garnet
 Glauconite
 Gold
 Graphite
 Gypsum

 Halite
 Hematite
 Hornblende

 Ilmenite

 Jadeite

 Kyanite
 Limonite

 Magnesite
 Magnetite
 Malachite
 Marcasite
 Molybdenite
 Monazite
 Muscovite

 Nepheline
 Nephrite

 Olivine
 Orthoclase

 Plagioclase
 Prehnite
 Pyrite
 Pyrophyllite
 Pyrrhotite

 Quartz

 Rhodochrosite
 Rhodonite
 Rutile
 Scapolite
 Serpentine
 Siderite
 Sillimanite
 Silver
 Sodalite
 Sphalerite
 Spinel
 Spodumene
 Staurolite
 Sulfur
 Sylvite

 Talc
 Titanite
 Topaz
 Tourmaline
 Turquoise

 Uraninite

 Witherite
 Wollastonite

 Zircon
 Zoisite


Blood Diamonds
Mount Rainier Volcanic Hazards
What Causes a Tsunami?
East Africa Rift
San Andreas Fault - Zoom In
Teaching Plate Tectonics with Drawings
What is Geology?
World's Biggest Tsunami


© 2005-2014 Geology.com. All Rights Reserved.
Images, code and content of this website are property of Geology.com. Use without permission is prohibited. Pages on this site are protected by Copyscape.