Natural Bulgarian Sugar Quartz with Fluorescent Calcite 78g

The outer surface of this Bulgarian piece is one continuous crust of sugar quartz, countless tiny quartz points grown shoulder to shoulder over a rolling, mounded core. The color is a cool pale grey that lifts toward white along the raised ridges, with a slightly deeper grey settling into the hollows between them, and the fine crystal texture gives the whole surface a frosted, granular finish. Small bladed calcite crystals are scattered singly and in pairs across the crust, clear to milky white and standing well above the quartz around them, and it is these calcite areas that react under UV light.

Sugar quartz is the trade name for this kind of dense micro-crystalline coating, formed when a late generation of quartz crystallizes across an earlier surface. The piece comes from the Krushev dol mine in the Madan ore field of the Rhodope Mountains, one of the Bulgarian lead-zinc workings that supplies most of the country's collector minerals. It is untreated, exactly as it came out of the ground. Quartz sits at 7 on the Mohs scale and calcite at 3, so the calcite blades are the delicate part of the piece, which makes it best suited to a display shelf or a UV cabinet.

Natural sugar quartz with fluorescent calcite, Krushev dol mine, Bulgaria, single piece.