Opal
Tsehay Mewcha, Wegeltena, Delanta Woreda, South Wollo Zone, Amhara Region, Ethiopia
14.4 cm tall x 11 cm wide
Precious opals are a hydrated amorphous form of silica (amorphous meaning a non-crystallized solid), unlike crystalline forms of silica, which are classed as minerals. Australia is the locality most associated with precious opal. The precious opals of Ethiopia were only discovered recently in 2008.
Opals are formed over thousands of years when rain frees spherical silica particles from sandstone. These microscopic particles spread deep into underground cavities and are then compressed into a closely-packed interlaced structure. When miners bring them forth from the earth to the surface, sunlight travels through this microstructure creating the dazzling kaleidoscope of flashing rainbow colors that we see here.
This opal may be unique. The colors are like no other we have seen from Ethiopia. There are several names given to opal (Black Opal, Boulder Opal, Fire opal, etc.). This piece begins an entirely new genre - Candy Opal.
This specimen was featured in our Candy exhibition.