CHRYSOCOLLA
Specimen chc-37
$ 29.00Dims: 2.16x1.74x0.95" (5.48x4.43x2.40cm)
Wt: 2.95oz (83.6g)
Ray Mine, Pinal County, Arizona, USA
This is not a "druzy chrysocolla" specimen, but rather a "druzy quartz over chrysocolla" specimen. The quartz crystals are colorless but thick enough that the underlying layer of chrysocolla does not show through. The chrysocolla occurs in a thin shell lining the cavity under the quartz, and in several other areas totalling about 30% of the surface. Most of this is dull, opaque, and turquoise blue, but in a few areas the agatized chrysocolla is deep blue and translucent, with a vitreous luster. This is unusually pretty, and it is unfortunate that more of the exposed mineral does not have this form. Close examination with a loupe reveals that the thin layer between the quartz and the host rock is actually a radial growth of the deep translucent blue mineral with only a thin coating of the lighter, opaque mineral. That host rock looks like obsidian - it is black, vitreous, and exhibits a conchoidal fracture.