opal
/ˈoʊpəl/ noun C1- A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity, of the chemical formula SiO₂·nH₂O.
- A precious gem, an iridescent gemstone found in the opal-silica mineral substrate (potch)
- The colour of opal: any shade of blue with bright flecks of other colours, such as white, yellow, and red.
- A colloquial name used in molecular biology referring to a particular stop codon sequence, "UGA."
- Any of various lycaenid butterflies of the genus Nesolycaena.
Plural opals
From the library
“Ah yes, I recall the case; it was concerned with an opal tiara.
The crowd moved to and fro in the rooms like an ebb and flow of turquoises, rubies, emeralds, opals, and diamonds.
It was about six o’clock in the evening; an opal-colored light, through which an autumnal sun shed its golden rays, descended on the blue ocean.
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