Gem: Topaz, and possibly phenakite
Weight: 3.89 ct.
Dimensions: 9.5 x 9.5 x 6.4
Clarity: N/A - specimen grade with sections of pure transparency, and included sections. Visually, it is gemmy, in general,
Origin: Harvard University's 1920's digsite on South Baldface Mountain in Chatham, New Hampshire
Comments:
This very neat specimen comes from the tailings of the very old digsite that Harvard University explored in the 1920's. They blasted and extracted some very impressive specimens and also made gems of topaz, smokey quartz, phenakite, amazonite, and a few other odd and interesting mineral types, typical of myriolitic granitic pegmatite. In this type of rock, pockets of crystallized minerals are encased in fine-grained granite.
The crystallization is pretty good all around. The bootom is cleaved off of the matrix, and there are a couple of very small nicks around the bottom edge. The backside is completely crystallized, and looks like it separated from the crystal next to it, like it probably has a twin-contact on another crystal. The specimen sits best facing flat side forward, since it is the largest crystallized face, AND it has another crystal growinng out of that face. The small crystal is either another topaz, or could also be a phenakite crystal. I don't have a way to test for which, though an expert on crystal structure with a microscope might be able to tell.