出典:Wiktionary
chloritoid (countable かつ uncountable, 複数形 chloritoids)
出典:Wikipedia
出典:『Wikipedia』 (2010/11/28 18:29 UTC 版)
Chloritoid is a silicate mineral of metamorphic origin. It is an iron magnesium manganese alumino-silicate hydroxide with formula: (Fe,Mg,Mn)2Al4Si2O10(OH)4. It occurs as greenish grey to black platy micaceous crystals and foliated masses. Its Mohs hardness is 6.5, unusually high for a platy mineral, and it has a specific gravity of 3.52 to 3.57. It typically occurs in phyllites, schists and marbles.