Natural Big Quartz with Calcite and Pyrite Cluster 1.2kg

The face of this large plate is paved with short, stubby quartz crystals, each one terminated and packed tight against its neighbours, in a soft smoky grey-green that lets light through at the tips. Across that quartz bed run strings of small white calcite beads, rounded and closely spaced, looping and curling over the crystal heads in rings and trailing lines. A few pyrite grains show as small bright metallic points, and the underside breaks away into dark grey host rock.

The beaded calcite is what makes this plate unusual. Rather than growing as single crystals, the calcite has crystallized in chains of tiny rounded grains that follow the contours of the quartz beneath, and the white against the grey-green is the strongest thing about the piece. It comes from the Bulgarian lead-zinc veins of the Rhodope Mountains, where quartz, calcite and pyrite share the same pockets. Untreated. Quartz is 7 on the Mohs scale and calcite 3, and at 143mm across and 1.2kg this is a shelf specimen rather than a tray piece.

Natural quartz with beaded calcite and pyrite, Bulgaria, single piece.