(n) :
(mineralogy) An aluminium nesosilicate mineral, Al₂SiO₅, which can be cut into a gem and displays strong pleochroism, shifting between red, green, and yellow.
(n) :
(mineralogy) An aluminium nesosilicate mineral, Al₂SiO₅, which can be cut into a gem and displays strong pleochroism, shifting between red, green, and yellow.