An Investigation of Greenish Quartz found at the Thunder Bay Amethyst Mine Panorama, Thunder Bay, Ontario, Canada, and Similar Localities

Laura B. Hebert

Greenish quartz has been reported at a number of deposits throughout the world. The material from Thunder Bay Amethyst Mine Panorama is generally pale greenish gray.  Samples of greenish quartz collected from three other amethyst-bearing localities: Farm Kos and Farm Rooisand, Gamsberg Area, Namibia, are more intensely colored.  The area between Kalomo and Mapatiqya, Zambia, also produces greenish quartz. Quartz from Southern Bahia, Brazil, is more intensely green. Spectacularly green quartz is reported from Coos County,  New Hampshire, USA.

A detailed study of quartz from the Thunder Bay deposit shows that the green quartz is
part of a color-gradational mineralization sequence involving macrocrystalline quartz of other colors and chalcedony.

For all localities, colors within the quartz are consistently correlated with the speciation of hydrous components, as darker green samples incorporate larger amounts of molecular water than paler greenish gray samples, colorless samples, and amethyst.  The appearance of strong hydroxyl peaks in the infrared spectra is limited to amethyst and colorless varieties.