Sand calcite is a cluster of calcite crystals with gray sand inclusions. An exceptional specimen with a cluster of formed crystals of calcite heavily included by sand grains. The specimen comes from an area to the north of Fontainebleau, France known as Bellecroix. The calcite crystals are believed to have formed within cavities in limestone horizons which underlay beds of sand. The sand is thought to have infiltrated the limestone cavities while the calcite crystals were growing, giving them the distinctive sculptured sandstone appearance. Dimensions: 3.5" L x 1.75" W x 1.25 " H.