Dims: 5.10x3.67x2.29" (12.96x9.32x5.82cm)
Wt: 11.04oz (313g)
Chalk Mountain, Spruce Pine, North Carolina, USA
This is a porous intergrowth of very white, translucent hyalite blobs (a variety of opal). Most of the specimen is hyalite, although there is a coating on the back that is an opaque white mineral, plus the back has several areas of some dark rock. The specimen is rather porous, and some of the hyalite is transparent. Still, the specimen is not very interesting unless it is exposed to ultra-violet light, then it glows a very bright green. The opaque mineral on the back also glows a barely perceptible pink, just enough to make me believe that it is calcite.