noun
cryolite
A mineral (sodium hexafluoroaluminate) used historically in aluminum smelting. Technical term in mineralogy.
氷晶石はアルミニウムの精錬に使われる鉱物だ。
Cryolite is a mineral used in aluminum refining.
From 氷 (ice) + 晶 (crystal) + 石 (stone), referring to its ice-like appearance. The exact historical derivation is uncertain.