Natural Big Quartz Cluster with Paper Calcite and Sphalerite from Bulgaria 1428g

A large, low plate with a dark base of sphalerite and galena, and over it a dense growth of elongated quartz crystals lying in every direction. The quartz carries a fine sandy carbonate film that turns it a warm beige-tan rather than white, and the crystals cross and overlap in loose bundles across the full 180mm length. On the upper right a broad patch of the same sandy carbonate spreads over the surface as a thick granular crust. Thin flat calcite blades, the habit collectors call paper calcite, sit among the quartz where the coating thins.

Paper calcite is calcite grown as very thin flat plates rather than blocky rhombs, and the sandy carbonate coating on the quartz here comes from the same late stage in the pocket. From the Bulgarian lead-zinc field in the Rhodope Mountains. Untreated. Quartz is 7 on the Mohs scale, calcite 3 and sphalerite 3.5 to 4, and the calcite blades are the fragile part. At 1428g and 180mm across this is a large display plate.

Natural quartz with paper calcite and sphalerite, Bulgaria, single piece.