A HIGHLY UNUSUAL and showy two-sided specimen of lustrous, translucent, striated, colorless calcite scalenohedrons to 2.6 cm on a sparkly, hollow dolomite cast after a large calcite scalenohedron from Guanajuato, Mexico. Very trivial bruising to a few calcite crystals is certainly not detracting on this very fine specimen. 6.8 x 6.5 x 3.9 cm