noun
celestite; celestine
A mineral consisting of strontium sulfate, typically pale blue or colorless. Used in geology and mineralogy.
天青石はストロンチウムの主要な鉱石鉱物です。
Celestite is the primary ore mineral of strontium.
From 天 (ten, 'sky') + 青 (sei, 'blue') + 石 (seki, 'stone'), referring to its typical sky-blue color.