Herkimer Diamonds Double Terminated Quartz Silicate Group

Physical Features

1. Color- Clear.

2. Streak- White.

3. Luster- Glassy.

4. Cleavage- None.

5. Transparency- Transparent.

6. Fracture- Conchoidal.

7. Hardness- 7.

8. Forms- Faceted.

9. Crystal system- Doubly terminated.

Herkimer Diamonds have a typical hexagonal habit such as quartz, but instead of having a termination on one end they are both doubly terminated. This is a result of the crystals growing with little or no contact with their host rock (dolomite), making Herkimer Diamonds very rare. These diamonds were first discovered in exposed outcrops of dolomite, where they form in cavities, and pockets within the dolomite, sometimes the pockets are also frequently filled with druzy quartz crystals. These occurrences can be found in Herkimer New York and around the little falls area of middleville. There have been other doubly terminated diamonds found in Arizona, Afgahanistan, Norway, the Ukraine, and China. Although they are the same, they are not considered Herkimer Diamonds.