E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
O’pal.
From the Greek ops (the eye). Considered unlucky for the same reason that peacocks’ feathers in a house are said to be unlucky. A peacock’s feather, being full of eyes, act as spies in a house, prying into one’s privacy. Similarly, it is unlucky to introduce the eye-stone or opal into a house, because it will interfere with the sanctity of domestic privacy. (See CERAUNIUM).
