Chinese Name：閃靈鐨、赫基蒙水晶、赫基蒙鑽石
English Name：Dual Head Quartz, Herkimer Crystal, Herkimer Quartz, Herkimer Diamond, Herkimer-style Quartz
Chemical Composition：SiO2
Crystal System：Trigonal
Hardness：7.0
SG：2.65
RI：1.544 - 1.553 (Double refraction +0.009)
Birthstone：April 
Related Chakra：Balance, clean up every chakra of body, especially to the crown
Locality： (Herkimer County)(New York) USA, (New Mexico) USA, Argentina, Austria, Canada, Germany, Italy, Japan, Mexico, Pakistan, Poland, South Africa, Spain, UK,
Remarks：Natural dual head quartz, without any polish and cutting, pointed head on both sides with short prism in the middle (sometimes the prism can be extremely short), the outlook resemblance to the diamond rough octahedron, and also because it's been found from Herkimer County of USA, thus people call it Herkimer Diamond.
Source：Herkimer Quartz are found in limestone rock which has been dated at about 500 million years old.
It's usually doubly-terminated, often associated with inclusions of petroleum and/or associated with oil or coal deposits within sedimentary rocks. Might contain a black hydrocarbon inclousions. All such quartz crystals formed under low-temperature hydrothermal conditions in the sedimentary rocks.