Answer | Crossword Clue |
---|---|
hypersthene | A greenish rock-forming mineral of the orthopyroxene class, consisting of a magnesium iron silicate |
pyroxenes | Any of a large class of rock-forming silicate minerals, generally containing calcium, magnesium, and iron and typically occurring as prismatic crystals |
hornblendes | A dark brown, black, or green mineral of the amphibole group consisting of a hydroxyl alumino-silicate of calcium, magnesium, and iron, occurring in many igneous and metamorphic rocks |