MOTHER OF PEARL.

MOTHER OF PEARL. The shells of several species of molluscous animals are popularly known as mother of pearl, those, for instance, of Avicula macroptera and of some species of Haliotis. To the shells, however, of Avicula (Meleagrina) margaritifera the term mother of pearl is properly applied. This species has a wide distribution in tropical seas. Macassar mother of pearl, from white-edged shells, is the most highly prized; the Manila yellow-edged shells are not much inferior; and the shells from some parts of Australia are also of a high quality, but those from Sydney and Auckland are of a gray texture. The poorest shells come from Panama. By far the greatest supply of mother of pearl is now got from the north and north-west of Australia, but large quantities also are obtained from the Straits Settlements, the Persian Gulf, and the islands of the Pacific. The annual value imported into England reaches £300,000. In Austria, France, and Britain thousands of persons work it for inlaid-work, fans, buttons, cutlery handles, trays, &c. The shell of the large pearl-oyster is thick, of slow growth, and sometimes measures nearly a foot across. For the beautiful play of its colours, see IRIDESCENCE.