opal
Pronunciation:
/ˈəʊpəl//ˈoʊpəl/noun
Definitions
A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity, of the chemical formula SiO2·nH2O.
A colloquial name used in molecular biology referring to a particular stop codon sequence, "UGA."
Any of various lycaenid butterflies of the genus Nesolycaena.