Notable locations in Williamsburg: Williamsburg Sport Complex (A), Sport Hill Country Club (B), Iowa County Ambulance Williamsburg (C), Williamsburg First Responders (D), Williamsburg Public Library (E), Williamsburg Police Department (F), Williamsburg Fire Department (G). Display/hide their locations on the map.
Types of Opal. Opal is a hydrated amorphous form of silica; its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classed as a mineraloid, unlike the other crystalline forms of silica, which are classed as minerals.
Other significant deposits of precious opal around the world can be found in the Czech Republic, Slovakia, Hungary, Turkey, Indonesia, Brazil (in Pedro II, Piaui), PiauÃ­ Honduras-Erandique Lempira Lempira, Department guatemala And. nicaraguaeruvian opal (also called blue opal) is a semiopaque to opaque blue-green stone found in Peru, which is often cut to include the matrix in the more opaque stones. It does not display pleochroism. Blue opal also comes from Oregon in the Owhyee region, as well as from Nevada around Virgin Valley.