Opal

Opal is a hydrated amorphous form of silica (SiO2·nH2O) which its water content may range from 3 to 21% by weight, most of the opal from Wollo, Ethiopia, is hydrophane. The term hydrophane comes from the Greek words meaning “water-loving” and describes their ability to absorb water and change from opaque or semi-translucent to translucent […]