Spodumene

Spodumene is a member of the Pyroxene Group of minerals that includes Aegirine, Diopside, Hedenbergite, Hypersthene, Jadeite, Petedunnite and Spodumene. Spodumene is also a member of the Spodumene Family of minerals that includesHiddenite, Kunzite, and Spodumene. It is a beautiful gem that is found as colorless, yellow, pale green, deep green (Hiddenite), pink (Kunzite), blue-green and, rarely, blue. Spodumene is strongly pleochroic, meaning it has a color intensity difference when viewed from different directions. It is a very difficult gem to facet because of its strong pleochroism, easy cleavage, and splintery fracture.

There are many localities for fine Spodumene crystals including Nuristan district, Laghman Province, Afghanistan; Minas Gerais, Brazil; Maharitra, Mt. Bity, and Anjanabonoina, Madagascar. In the USA, giant crystals in the Etta mine, near Keystone, Pennington County, South Dakota; at Hiddenite, Alexander County North Carolina; and from the Pala district, San Diego County, California.

Category: Inosilicate
Formula: LiAl(SiO3)2
lithium aluminium silicate
Crystallography: Monoclinic – Prismatic
Crystal Habit: Spodumene: Crystals are prismatic, typically flattened and striated, to 12.5 m and 54 t. Commonly massive.
Twinning: Common on [100].

 

Cleavage: [110] Good, [100] Good, [010] Partings
Fracture: Uneven to Subconchoidal
Tenacity: Brittle
Hardness (Mohs): 6.5 – 7.0
Density: 3.03 – 3.23 (g/cm3)
Luminescence: May show Yellow, Orange or Pink fluorescence under LW and SW UV.
Radioactivity: Not Radioactive

 

Color: Colorless, White, Gray, Yellow
Transparency: Transparent to Translucent
Luster: Vitreous, Dull; Pearly on cleavages
Refractive Index: 1.648 – 1.679  Biaxial ( + )
Birefringence: 0.014 – 0.027
Dispersion: Weak; r < v; 0.012
Pleochroism: Distinct; X = Colorless; Y = Yellow; Z = Greenish Yellow