E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Meerschaum (2 syl., German, sea-froth.)
This mineral, from having been found on the sea-shore in rounded white lumps, was ignorantly supposed to be sea-froth petrified; but it is a compound of silica, magnesia, lime, water, and carbonic acid. When first dug it lathers like soap, and is used as a soap by the Tartars.