ABOUT PEARLS.

Daily Telegraph (Napier), Issue 3197, 27 September 1881, Page 4

ABOUT PEARLS.

Prof. T. 0. Archer mentions that there are three principal kinds of these mother-o-pearl , shells brought to markeb at Manilla (which is the depot for the pearl oyster trade). The valves realise from £2 to £-1 per hundredweight. One kind is knovm as the silver-lipped oyster, from the Society Islands; another the black-lipped variety, from Manilla ; the third, from Panama, "is smaller than the others. About 250 tons of these shells are annually imported into Liverpool alone. They also yield the "oriental" pearls of commerce. The principal pearl fisheries are in the Persian Q-ulf and Ceylon. Pearls are produced by many bivalves, but by none in greater perfection than by the Meleagrina margaritifera They are caused by particles of sand or other foreign substance finding its way into the cavity of the valves, and getting between the animal and its shell ; the irritation causes a deposit of nacre, forming a projection on the interior, generally more brilliant than the rest of the shell. Completely spherical pearls can only be found loose in 'the muscles or other soft parts of the animal. The Chinese obtain them artifically by introducing into the living Hyria foreign substances, such as of inother-0 , -pearl fixed to wires, which tkius become coated with a more brilliant material. Similar prominences and concretions—pearls which are not pearly—are formed insirle poi'cellanons shells. These are as variable in color as the surface on which they are formed. They are pink in CTurbinelia nnri Mtrombus ; white in Ostrea ; white or glo3sy, purple or black in Mytilus ; rose-colored und translucent in Pinna. The pearl fisheries of the Persian Q-ulf and Ceylon give employment annually to several hundred boats and many thousand men. The entire amount of revenue derived from the pearl fisheries of Ceylon in nine years (from 1828 to 183*7), according to Mr James Steuart, the Inspector of Pearls Hanks, was £21>7,131, but it has since decreased very considerably. Mr Hope possessed a pearl measuring two inches in length and four inches in circumference, and weighing 1,800 grains. This is said to be the largest pearl known. A very fine pearl bouton was sold in London in 1860 for £2,000 ; ifc measui'ed about five-eighths of an inch. Good pearls of two grains weight are common, and fetch about 7s 6d each ; pearls weighing five grains are worth £2 each • ripn-ls of ten grains weieht sell for £7 and £8 apiece. But the best market for pearls is in India itself, where they are more highly esteemed than in Europe, and realise far higher values. —Cassell's Natural History,