Email Me .
Dwarves' Earth Treasures Online Museum:
Centennial Datolites
Centennial #2 Mine, Centennial, Houghton Co., Michigan
 .
.    There was a story of the miners hitting on a huge seam of datolites and they used water hose to wash the datolites out of the mud-filled seam. Those datolites used to be one of most commonly encountered beside those coming from Delaware and Caledonia, but they are now becoming scarce. It is common for the Centennial datolites to contain native copper inclusions and some of those datolites got their green and rarely sky blue colors from the weathering of copper inclusions by ancient brine waters  Today, most of the rocks had been hauled from the mine dumps to be crushed for purposes of road-paving, so there may be not much left coming from the Centennial Mine. Recently, there is a report on the fact that the blue color in some datolites may be due to kinoite inclusions.


Typical Centennial Datolite with copper inclusions.
I found this as a rough  in a rock pile at a Rock Shop in Arizona.

Teal-colored with some copper inclusions, Large "mulit-datolite" specimen with greenish colors
Datolite with true sky blue(turquoise) color
very rare.		 Greenish due to copper inclusions
Another very rare datolite with bluish colors possibly from kinoite inclusions Datolite filling in epidote lined vug with copper inclusions
Found by Jeffrey A, August 1996