Multicolored flashes of red, orange, green and yellow flash brightly on and off inside this outstanding Ethiopian opal as you move it in the light. The display surface is almost the entire size of the specimen, and the colors are amazingly bright and very showy. Opal is a hydrated amorphous form of silica with a water content that is usually between 6 and 10%. Because of its amorphous character, it is classed as a mineraloid. The colors and gemmy quality of this specimen are really quite impressive.