noun Download 🔗Share A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity, of the chemical formula SiO2·nH2O. Examples : "My aunt collects beautiful opals, admiring their shimmering colors despite knowing they are softer than quartz and can scratch easily. " mineral geology material substance science Chat with AIVocabulary GamePractice Reading
noun Download 🔗Share A colloquial name used in molecular biology referring to a particular stop codon sequence, "UGA." Examples : "In genetics class, we learned that "opals," or UGA stop codons, signal the end of protein synthesis. " biology biochemistry technical Chat with AIVocabulary GamePractice Reading
noun Download 🔗Share Any of various lycaenid butterflies of the genus Nesolycaena. Examples : "While hiking in the rainforest, the butterfly enthusiast excitedly pointed out a group of opals fluttering around a flowering bush. " animal insect biology nature Chat with AIVocabulary GamePractice Reading