A fluid inclusion analysis and history of Herkimer Diamonds, Mohawk Valley, New York

A fluid inclusion study was conducted on Herkimer Diamonds from vugs throughout the upper Cambrian Little Falls Dolostone of the Mohawk Valley, New York State. Salinities (wt. % NaCl) determined for the fluid inclusions present in the Herkimer Diamonds ranged from 16.15%-20.07%. Homogenization temperatures ranged from 167.5°C-180.2°C. These inclusions are similar to the high temperature type W2 inclusions of O'Reilly and Parnell (1999), consistent with formations under gas window conditions (>200°C). This similarity in data from 65 fluid inclusions from various sample locations and stratigraphic units, suggests a coeval flow of hydrothermal fluid through faulting and vugs in the Little Falls Dolostone.;The geologic history of the Herkimer Diamonds dates back to approximately 500 million years ago. Human interaction with these crystals has been documented in the late 1500's to early 1600's. Since this time, an increase in interest of geologist and collectors has warranted not only scientific intrigue, but also economic growth in the Mohawk Valley, New York.;Keywords: Liberal Studies, Dr. Adam Schoonmaker, fluid inclusion assemblages, hydrothermal, hydrocarbon.