“MORPHOLOGY: Twinned COLOUR: Colourless (purple phantoms) A cavity in the ironstone matrix is lined with decomposed Siderite crystals (Goethite). Settled on top is a group of transparent interpenetrating Fluorite crystals. The crystals appear colourless when viewed straight on but appear a slight purple colour when the crystal face is viewed from the underside, due to the presence of a purple 'phantom' layer. ”