A polymorph is a mineral that shares the same chemistry but a different crystal structure with another, or other, minerals. These inclusions are arranged in regular symmetrical shapes. Color is white, red, brown, orange and green. Luster is vitreous. Transparency crystals are transparent to translucent.
Cleavage is good in two directions.
Fracture is splintery to subconchoidal. Streak is white. Associated Minerals are cordierite , biotite , feldspars , quartz , kyanite and sillimanite . Index of refraction is 1.632-1.638.