Spodumene.
Reading edition
Spodumene is sometimes cut and polished as a gem, but its peculiar cleavage makes it a bad stone for the lapidary to cut and the jeweler to mount.
Its hardness is 6.5 to 7, specific gravity 3.13 to 3.19, and lustre, vitreous to pearly.
Grayish-green, greenish-white, and sometimes yellow or faint red are the colors. Its composition is:
Silica 64.2
Alumina 29.4
Lithia 6.4
Acids do not attack spodumene, and under the blow-pipe it fuses to a white glass.
This mineral is found in Sweden, the Tyrol, Ireland, Scotland, and the United States.