Spodumene

spodumene [′spä·jə‚mēn]

(mineralogy)

LiAlSi₂O₆A white to yellowish-, purplish-, or emerald-green clinopyroxene mineral occurring in prismatic crystals; hardness is 6.5-7 on Mohs scale, and specific gravity 3.13-3.20; an ore of lithium. Also known as triphane.

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Spodumene 

(also triphane), a mineral of the clinopyroxene group, which belongs to the inosilicate class of silicates. The chemical composition is LiAl[Si₂O₆]. Spodumene forms elongated prismatic crystals 1–10 cm in length; the length of the crystals sometimes reaches 1 m and, less frequently, 10–16 m. Colors are gray, yellowish, greenish, or pinkish, but sometimes the mineral is colorless. The transparent pink and violet-pink varieties are called kunzite, whereas the emerald green varieties are called hiddenite.

Spodumene has a vitreous luster, a hardness of 6.5–7 on Mohs’ scale, a density of 3,100–3,200 kg/m³, and a perfect cleavage along the prism. When heated in the temperature range 950°-l 100°C, natural α-spodumene changes to the β-modification of the crystal structure (β-spodumene).

Spodumene occurs in granitic pegmatites of the sodium-lithium type in association with quartz, microcline, albite, beryl, lepidol-ite, tantalite, and, sometimes, pollucite and other minerals. It often alters to aggregates of eucryptite (LiAlSiO₄) or aggregates of sericite with albite. In the waste mantle, it alters easily to clay minerals. Spodumene is the primary mineral of lithium ores; kun-zite and hiddenite are gems. In other countries, spodumene is used in the production of ceramics.

REFERENCES

Ginzburg, A. I. “Spodumen i protsessy ego izmeneniia.” Tr. Mineralogicheskogo muzeia AN SSSR, 1959, issue 9.
Gordienko, V. V. Mineralogiia, geokhimiia i genezis spodumenovykh pegmatitov. Leningrad, 1970.
Ginzburg, A. I., and G. P. Lugovskoi. “Mestorozhdeniia litiia.” In Rudnye mestorozhdeniia SSSR, vol. 3. Moscow, 1974.

A. I. GINZBURG