Witherite with Baryte and Alstonite

Two fine, double terminated greyish-white crystals of Witherite are perched on a bed of small Alstonite crystals, from Alstonite’s joint type locality at Fallowfield mine at Acomb near Hexham in Northumberland. The smaller Witherite crystal measures 2.2 cm tip to tip; the larger crystal 3.3 cm, although the lower half of the double termination is not complete due to contact with the matrix. The Witherite’s semi-matt lustre suggests they are coated with a very thin film of Baryte. All the Alstonite crystals are to about 2 mm across and are perfectly terminated. The underside of the matrix is composed of intergrown platy colourless Baryte. A super example of these two rare British barium carbonate minerals.