Specimens of fluorescent crystalline baryte from Reigate, Surrey, UK. Baryte (also spelt barite) is a widely occurring mineral consisting of barium sulphate. Any barite specimen is incredibly dense, with small pieces even feeling heavier than they appear, which is surprising, considering it is a non metallic mineral. This density was how the mineral obtained its name, being derived from the Greek word 'βάρυζ' meaning heavy. It occurs in a range of environments and deposited via many processes including biogenic, hydrothermal and evaporation, among others. Commonly occurring in lead-zinc veins hence some of the samples contain galena (lead sulphide) as well. These particular samples of baryte are crystals with various shades of yellow colour and fluoresce a pale green/yellow under shortwave UV light. The crystals are incomplete and therefore show no identifiable crystal system. Specimens are approximately 1 - 3 cm in size and are supplied in small polythene bag with an information label, these pieces are ideal for mineral and crystal collectors or collectors of British minerals.