The rounded grains with good cleavage in the plane-polarized view below are diopside. The surrounding material is mostly calcite. The diopside has high relief because its refractive index is strongly different from the calcite.
Same field in crossed polarizers. The bright interference colors are typical, as is the occurrence. Diopside is a common mineral in calc-silicate marbles.
Created 10 Oct 1997, Last Update 16 December 1999
Not an official UW Green Bay site