Opal consist 3% - 21 % water, it comes in the category of mineraloid. In the early 1990s a new type of opal surfaced in Ethiopia, which was brown material in nodule. During year 2008 opal from Wollo was discovered. Ethiopian fire opals have striking pattern formations which make each opal unique. Some opals have diverse play of colors from Neon reds, oranges, green, blue, white, yellow, brown and a fire color. Some Ethiopian opal has points displaying spectral colors. There are also some "rainbow" opals, where each patches of play-of-color display the entire rainbow of spectral colors. Some Ethiopian opal has digit patterns, others has fossilized plants in them.
Mohs hardness 5.5 - 6.5
Synthetic Opal:-
Synthetic opal: RI 1.440 - 1.450; opt. isotropic; SG 1.74 - 2.07; Colours: colourless, white, black, red; Play of colour: red, orange, yellow, green, blue, violet; Transparent to opaque; Hardness 5.5 - 6.5. Clearly separated colour patches, "lizard-skin effect", columnar structure perpendicular to the "lizard-skin effect" - Gemmological Tables, Ulrich Henn and Claudio C. Milisenda, 2004, p 1
Significant Gem Localities:- Basically From Ethopia but also from other place Australia, Brazil, Canada, Indonesia, Mexico, Peru, USA.
No comments:
Post a Comment