A Herkimer Diamond is a double terminated clear Quartz Crystal that comes out of the ground looking like it’s been cut & polished. These 450 million-year-old gems are found in and around Herkimer County, New York, USA. Countless varieties in formation, such as scepters & skeletal, tend to be specific to the locations they are found throughout the area.
Exposing them requires sledgehammering into native bedrock, Dolostone that has hollow cavities or “vugs” containing sometimes perfect AAA+ grade water clear floaters that have no blemishes, no inclusions or contacts from another crystal.
Some crystals form firmly attached to the host rock are called “matrix specimens”. Inclusions of black hydrocarbon are most common. Pyrite can also occur within the crystals. An intact interior pocket of trapped water with an air bubble that moves freely is referred to as an enhydro. Intact enhydros are rare; changes in temperature and pressure tend to expand the water, causing it to blowout, leaving a fracture where the water escaped.
Herks range in size from micro 1mm to over 10 inches and also form in clusters of multiple interlocking stones.