A pyroxene is a type of pleochroic igneous silicate rock. It appears in diverse colours depending on the metallic element in its ionic crystal structure. In Greek superstition, they were thought as the impurities of lava forming as crystals found embedded in volcanic glass, hence the term "fire strangers". Their Japanese naming instead has more relation to the xenolithic nature of the latter meaning, referring to the jewel content that was widely treasured and coveted amongst the nation's greatly igneous land composition.
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