n. a quartzlike form of hydrated silica, usu. white or colourless and sometimes showing changing colours, often used as a gemstone. opal glass a semi-translucent white glass.
[ F opale or L opalus prob. ult. f. Skr. upalas precious stone ]
OPAL
Meaning of OPAL in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012