OPACULAR
O*pac"u*lar, a.
Defn: Opaque. [Obs.] Sterne.
OPAH
O"pah, n. (Zoöl.)
Defn: A large oceanic fish (Lampris quttatus), inhabiting the Atlantic Ocean. It is remarkable for its brilliant colors, which are red, green, and blue, with tints of purple and gold, covered with round silvery spots. Called also king of the herrings.
OPAKE
O*pake", a.
Defn: See Opaque.
OPAL O"pal, n. Etym: [L. opalus: cf. Gr. upala a rock, stone, precious stone: cf. F. opale.] (Min.)
Defn: A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.
Note: The precious opal presents a peculiar play of colors of delicate tints, and is highly esteemed as a gem. One kind, with a varied play of color in a reddish ground, is called the harlequin opal. The fire opal has colors like the red and yellow of flame. Common opal has a milky appearance. Menilite is a brown impure variety, occurring in concretions at Menilmontant, near Paris. Other varieties are cacholong, girasol, hyalite, and geyserite.
OPALESCE
O`pal*esce", v. i. [imp. & p. p. Opalesced; p. pr. & vb. n.
Opalescing.]