[mass noun]a mineral consisting of a silicate of calcium, magnesium, and aluminium, occurring typically as dark-green to brown prisms in metamorphosed limestone 符山石(由钙、镁、铝硅酸盐组成,多为暗绿至棕色变质石灰石结晶柱)
语源
early 19th cent.: from Greek eidos 'form' + krasis 'mixture'