Thursday, May 21, 2015

Ethiopian Welo Opals

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%. It is classified as a mineraloid, unlike the other crystalline forms of silica, which are classed as minerals.

The first published report of gem opal from Ethiopia appeared in the 1994, with the discovery of precious opal in the Menz Gishe District, North Shewa Province. The opal, found mostly in the form of nodules, is of volcanic origin and is found predominantly within weathered layers of rhyolite. In 2008, a new opal deposit was found near the town of Wegel Tena, in Ethiopia's Wollo Province. The Wollo Province opal was different from the previous Ethiopian opal finds in that it more closely resembled the sedimentary opals of Australia and Brazil, with a light background and often vivid play-of-color. Wollo Province opal, more commonly referred to as "Welo" or "Wello" opal became the dominant Ethiopian opal in the gem trade.
These opals are found in a round nodular form within a 3 meter thick layer of welded volcanic ash. Only about 1% of these nodules contain colour. The colours are very striking with red being common and blue quite rare which is the opposite to Australian opals. It has some magnificent patterns and brilliant colours and is called Ethiopian fire opal.
A newly discovered Ethiopian opal was found in Gondar which was at first called desert opal but it is from a plateau in the highlands. The main field which is creating a lot of excitement now is from a field called Welo. It is found in a plateau 2500 to 3299 meters. Only the locals are allowed to mine this field. They work the horizontal level of steep mountains. Opals from these fields are known as Ethiopian opal from wello.
Ethiopia Is considered one of the oldest inhabited human areas on the planet. The Awash Valley has one of the most complete preserved Australopithecine fossils around 3.2 million years old.