This is an incredible calcite specimen with exceptional clarity.  The extreme clarity in this find causes light to be refracted into a rainbow, and this piece is a great example of that because it's a single crystal.  Catch the video!  This calcite is from Lishui, China.  Pictured mounted on 2" acrylic base and mounting putty, included with purchase.  As with all of our minerals no two pieces are alike, offering a truly one-of-a-kind gift for mineral collectors, Minecraft fans, geologists, and rockhounds alike. 
 
More About Calcite
Calcite is a popular mineral with diverse crystal habits, vibrant colors, and widespread occurrence.  Specimens hail from all over the world and come in a multitude of mineral combinations.  Calcite most notably occurs with amethyst, fluorite, quartz, along with many others.  It’s a major component of limestone, marble, and chalk, as well as many other sedimentary rocks. It also forms in hydrothermal veins, as a precipitate from groundwater, and as a component of some igneous rocks.  Calcite has numerous industrial applications, including as a building material (limestone and marble), in the production of lime and cement, as a soil conditioner, in the manufacture of glass and ceramics, and as a source of calcium carbonate in dietary supplements.