Yellow Calcite sphere of depth and optical beauty. The crystals of calcite can form literally a thousand different shapes by combining the basic forms of the positive rhombohedron, negative rhombohedron, steeply, moderately and slightly inclined rhombohedrons, various scalahedrons, prism and pinacoid to name a few of the more common forms. There are more than 300 crystal forms identified in calcite and these forms can combine to produce the thousand different crystal variations. The 50mm Yellow Calcite Sphere is two inches in diameter. Information on how to place your order by fax or by telephone. Product Number YCSP50