This wonderful specimen contains a lazurite crystal that's partially exposed from its 1.3" wide marble/calcite matrix. This specimen was collected from the Sar-e-Sang District of Afghanistan, an area well known for its phenomenal lazurite crystals.
Lazurite is a vibrant blue mineral of the tectosilicates group, with the chemical formula Na6Ca2Al6Si6O24S2. It is the blue component in Lapis Lazuli and is most often found in massive forms, though in some cases it does form individual crystals. There is a location in Afghanistan that is well known for producing phenomenal lazurite crystals in a marble matrix. These specimens are highly sought after by both amateur and expert mineral collectors.