WITHERITE with BARYTE and ALSONITE

SPECIMEN DESCRIPTION

Two excellent, double terminated greyish-white Witherite crystals are perched on a bed of small Alstonite crystals, from one of Alstonite’s joint type localities, 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 about 2 mm across and are perfectly terminated. The underside of the matrix is composed of intergrown platy colourless Baryte. This is a super example of these two rare British barium carbonate minerals.