This calcite rhomb has naturally straight sides created from its distinct cleavage properties. The rhombohedral formation produces double-refraction, which is why this material is also known as Optical Calcite. When you look at objects through the calcite, it splits the rays of light and displays two images of the same object. This piece is a gemmy, translucent peachy pink, which is a result of the presence of manganese within its chemical makeup. Pink calcites are often called Manganoan or Mangano Calcite. The manganese can also act as an activator for fluorescence, especially under longwave UV. This specimen fluoresces very bright pink under UV light. 5cm x 4.5cm x 4.2cm 2" x 1 3/4" x 1 5/8" 238g (8.4oz)