This semi-precious gemstone is the result from small scale replacement of aluminium by chromium ions in the crystalline structure. This causes the stone to take in and absorb light over a narrow range of wavelengths. ...
GEMS,GEMSTONES,VARIETIES,PRECIOUS GEMS,GEMSTONES WORLD MARKET,GEM CUTTING,GEM POLISHING
This semi-precious gemstone is the result from small scale replacement of aluminium by chromium ions in the crystalline structure. This causes the stone to take in and absorb light over a narrow range of wavelengths. ...