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.
Currently, Australia produces around 95% of the world's opal for use in the jewellery industry. Other countries in which opal is found in small amounts include Honduras, Mexico, former Czechoslovakia, and Brazil, however these types of opal often differ in appearance.Australian opal is considered the finest in the world.ther countries in which opal is found in small amounts include Honduras, Mexico, former Czechoslovakia, and Brazil, however these types of opal often differ in appearance.