Simpsonite with Cesstibitantite from Vorony Tundry. Cesstibitantite is the brown spot below in the white. The Simpsonite is
white inbetween the dark minerals above. Cesstibitantite shows orange fluorescence and and Simpsonite shows blue fluorescence
under SWUV. Click on the picture to switch on the UV lamp.
[photo/collection: Maurice de Graaf]