Opal var. Hyalit – Valec, Doupov, Karlovy Vary, Czech Republic
 
 Sculptural Hyalite on matrix. This mineral usually occurs as a crust, the spherical crystals rarely build up to 2.5 cm. This variation of opal is highly fluorescent. Unharmed, rare collector's piece from the Czech Republic with a good luster and a strong reaction under UV light.