蛍ほたる石いし

noun, noun which may take the genitive case particle 'no'

fluorite; fluorspar

A common mineral (calcium fluoride) used in industry and as a gemstone. The Japanese name literally means 'firefly stone' because some specimens glow when heated.

• 蛍ほたる石いしはフッ化かカルシウムからなる鉱こう物ぶつです。

  Fluorite is a mineral composed of calcium fluoride.

• この蛍ほたる石いしの結けっ晶しょうは美うつくしい紫むらさき色いろをしている。

  This fluorite crystal has a beautiful purple color.