Opal

Opal, a variety of quartz, of which the finest kind, precious opal, is translucent, with blue or yellow tint, and when polished with a convex surface shows an admirable play of colours; it is found chiefly at Cerwenitza, Austria.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Oosterzee, Jan Jakob van * Open Secret, The
Omnipresence
Omphalë
Omsk
Onega, Lake
Onomatopœia
Ontario
Ontario, Lake
Ontology
Onyx
Oosterzee, Jan Jakob van
Opal
Open Secret, The
Open, Sesamë
Opera
Opera Bouffe
Ophelia
Ophicleide
Ophir
Ophites
Opie, John
Opinicus

Nearby

Opal in Brewer’s Dictionary of Phrase & Fable