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Chemical Formula | LiAlSi2O6 |
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Composition | Lithium aluminum silicate |
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Color | White, colorless, gray, pink, violet, green, yellow, brown. May display strong pleochroism. |
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Streak | White |
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Hardness | 6½ - 7 |
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Crystal Forms and Aggregates |
(Monoclinic) Usually as long, flat, prismatic crystals. Also occurs in rectangular crystals, tabular, bladed, as elongated crystals, as cleavage fragments, and massive. Crystals are often striated, sometimes deeply. |
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Transparency | Transparent to opaque |
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Specific Gravity | 3.1 - 3.2 |
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Luster | Vitreous, silky |
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Cleavage | 1,2 - prismatic at cleavage angles of 87º
and 93º (characteristic of minerals in the pyroxene group). May also exhibit parting in one direction. |
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Fracture | Uneven, splintery (with tough splinters) |
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Tenacity | Brittle |
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Other ID Marks | Often fluorescent: white to blue in SW, orange to orange-red in LW |
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Varieties |  Kunzite - Pink to violet,
transparent gem variety Hiddenite
- Light green, emerald-green, or yellow-green,
transparent gem variety |
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In Group | Silicates ; Inosilicates ; Pyroxene group |
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All About | Spodumene is strongly pleochroic. The pleochroism is easily observed in many
transparent crystals, where the color ranges from yellow
to violet when viewed at different angles. Some enormous Spodumene crystals are known to exist. The largest one ever found is a well-crystallized, 42 foot (12.8 meter) giant. The two Spodumene varieties, Kunzite and Hiddenite, are valued as gems. Unfortunately, though, Kunzite is notorious for fading upon prolonged exposure to sunlight. Deep pink gems will become nearly colorless. However, this detrimental process is fairly slow, taking several years. Transparent brown and green-brown specimens may be changed to light green by heat-treatment. Spodumene easily alters to other minerals (most often feldspar and mica) and into clay. "Pinite" is a name given to a green Muscovite pseudomorph after Spodumene. Sometimes, a crystal may be only partially altered, creating fascinating and intriguing specimens. |
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Uses | Spodumene is one of the most important ores
of lithium. Huge crystals are commercially mined for
extraction of this element. The transparent pink and
green varieties (Hiddenite and Kunzite) are used as gems. Well crystallized specimens are very popular among mineral collectors. Also see the gemstone section on Kunzite Also see the gemstone section on Hiddenite Also see the gemstone section on Spodumene |
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Striking Features | Distinct crystal habit, cleavage angles, and hardness |
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Popularity (1-4) | 2 |
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Prevalence (1-4) | 1 |
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Demand (1-3) | 1 |
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Distinguishing Similar Minerals |
Feldspars - slightly softer (6), different
cleavage and fracture Amblygonite - softer |
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Commonly Occurs With |
Quartz, Beryl, Tourmaline, Feldspars, Topaz, Lepidolite, Muscovite, Amblygonite |
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Noteworthy ocalities |
Fine transparent crystals come from several
localities in Minas Gerais, Brazil. One of the most
productive localities in regard to collector specimens of
gem-quality Spodumene crystals is Nuristan, Logham
Province, Afghanistan. Two additional well-known
occurrences are Carlow, Ireland and the Madagascar pegmatites. In the U.S., beautifully colored, transparent Kunzite is found in the Pala area, San Diego Co., California, together with Tourmaline. The only locality where emerald-green Hiddenite is found is Hiddenite, Alexander Co., North Carolina (the locality is named after the mineral). Other famous Spodumene localities are the Foote Spodumene mine, Kings Mountain., Cleveland Co., North Carolina; the Harding Mine, near Dixon, Taos Co., New Mexico; and Newry, Oxford Co., Maine. Two localities from which enormous crystals were extracted are Bernic Lake, Manitoba, Canada, and the Black Hills of South Dakota (namely the Etta Mine and Tin Mountain). |
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