purple of Cassius

[ kash-uhs, kash-ee-uhs, kah-see-uhs ]

noun

1. a purple pigment precipitated as a sol by the interaction of gold chloride and a solution of stannic acid and stannous chloride: used chiefly in the manufacture of ruby glass, ceramic glazes, and enamels.

Word History and Origins

Origin of purple of Cassius¹

1830–40; named after A. Cassius, 17th-century German physician

Example Sentences

Gold also, like silver, does not unite with oxygen readily, or remain in union with it at high temperature; therefore great care is required in the preparation of glass to be coloured by oxide of gold; the form in which it is used being generally that of the purple of Cassius, made by precipitating a salt of tin with a salt of gold.

From Project Gutenberg

In solution minute quantities of gold may be detected by the formation of “purple of Cassius,” a bluish-purple precipitate thrown down by a mixture of ferric and stannous chlorides.

From Project Gutenberg

When the gold is finely 193 divided, as in “purple of Cassius,” or when it is precipitated from solutions, the colour is ruby-red, while in very thin leaves it transmits a greenish light.

From Project Gutenberg

At one time, indeed, a gold compound known as purple of Cassius was so employed, but this soon became obsolete on the introduction of madder purple.

From Project Gutenberg

Purple of Cassius, or Cassius's Purple Precipitate, was discovered in 1683 by Cassius of Leyden.

From Project Gutenberg