Cut and polished jasper showing broad areas of internal color ranging from light yellow, brown to white (North Shoe). Source: Museum, GSE (Photograph by Sentayehu Zewdie)

Large size opal, dark brown base color with flashes of red, green and blue fire  (Yita Ridge, Mezezo, North  Shewa).Source: Tucci, 2005; http//www.rockngem

Rough opal on the international market. http://yabsera.en.ecplaza.net/
Oval cabochon of white precious
opal with brilliant green-orange
internal fire, from Menz Gishe
District, Mezezo. Source:
http://www.johnbetts-fineminerals.com/
Cut and polished opal shows an incredible array of colors (North Shewa).

Garnet crystals at Harakole (Oromia National Regional States,  Guji zone)

Rough Ethiopian opal on international market
Source:http://www.ecplaza.net

Introduction:

A gemstone or gem, also called a precious or semi-precious stone, is a piece of attractive mineralwhich when cut and polished is used to makee jwelry. Although not mineralized,some organic materials like amber, coral, ivory, pearl etc.; are used as gemstone.

Nodules of opal within rhyolitic ignimbrite covered by acidic ash. (Yita Ridge, Mezezo, North  Shewa) Source Geo-museum (GSE) (Photoraph by Sentayehu Zewdie).

Oval cabochon of white precious opal with brilliant green-orange internal fire, from Menz GisheDistrict,Mezezo.Source: http://www.johnbetts-fineminerals.com/