Natural Grey Chalcedony with Sugar Quartz 227g

A blocky wedge of grey chalcedony carrying a partial coat of sugar quartz. The chalcedony body is a dense, cool blue-grey, smooth and waxy where it is bare, and over roughly half the surface it disappears under a fine crust of pale quartz micro-crystals that runs in soft-edged patches from the top face down the sides. Where the crust is thickest it is almost white and frosted; where it thins, the darker grey shows through under a light dusting of crystal. A small opening on the upper left leads into a dark cavity lined with the same growth.

Sugar quartz is a late crystal coating that forms over an earlier chalcedony surface, and the contrast between the two textures, one waxy and solid, one granular and bright, is the appeal of this material. Bulgarian grey chalcedony of this kind comes out of the volcanic rocks of the Rhodope region. Untreated. Both chalcedony and quartz sit around 6.5 to 7 on the Mohs scale, so the piece is hard-wearing and takes handling well, and at 227g it works as a desk or shelf specimen.

Natural grey chalcedony with sugar quartz, Bulgaria, single piece.