New Deposit of Black Opal from Ethiopia

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New Deposit of Black Opal from Ethiopia


Opal was first discovered in Ethiopia in the early 1990s. Specimens from Mezezo in the historical Shewa province consist of nodules of a reddish brown volcanic rock with orange, reddish brown, or “chocolate” brown precious opal inside. The next major discovery occurred in 2008, when white precious opal was found in the province of Wollo near Wegel Tena, about 550 km north of Addis Ababa (F. Mazzero et al., “Nouveau gisement ďopales ďEthiopie dans la Province du Welo: Premières informations,” Revue de Gemmologie a.f.g., No. 167, pp. 4–5). This deposit still produces large amounts of white and crystal precious opal and occasionally some black material (Winter 2011 Lab Notes, pp. 312–313).

In 2013, yet another source was discovered in Wollo, at the Stayish mine near the town of Gashena (figure 1). This discovery has yielded mostly dark and black opal, along with some white and crystal opal. Although it is only now being reported, the deposit has been actively producing since 2013. It is set in a distinct opal-bearing layer in a mountainous area at an altitude of around 3,000 meters. It lies approximately 700 km northeast of Addis Ababa, more than 100 km from the historic town of Lalibela by road, and about 30 km north of the white opal deposit.


Like the white opal, the black opal is found at the contact zone between the volcanic rock series and the underlying clay-rich layer The layer is one in a sequence of repeating volcanic ash and ignimbrite layers. Field observations at different locations show that the opal-bearing layer is contained in a single stratum extending for tens and even hundreds of kilometers along the mountain belt. The opal-bearing clay layer is about 60 cm thick and contains opal of various quality and color. The black opal is retrieved from flat tunnels up to 15–20 meters long that are dug horizontally into the mountain slope by local villagers. The material generally comes in nodules and chunks 2–5 cm long, but 10 cm pieces have also been retrieved from this deposit

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