Rough Red Calcite by the pound gemini #EM-384 Emerald specimen in matrix

#EM-384 Emerald specimen in matrix from Colombia

and may be blue

#OP-428 Australian Boulder Opal

#TK-53 Box containing 5 small Tektite specimens

Rough Red Calcite by the pound gemini #EM-384 Emerald specimen in matrixRM RCAL Rough Red Calcite from Mexico. Pieces are approximately 1. 25 2 inches in size. Sold by the pound. Chemical Composition: Calcium Carbonate, CaCO3 Hardness: 3 Occurrence: Calcite crystals occur in a variety of forms, including hexagonal , trigonal, often resulting as a rhombohedron. Our optical calcite specimens are natural shaped crystals (not cut), which exhibit double refraction (an object viewed through the crystal appears as a double