AUSTRALIAN GEM STONES.

Star (Christchurch), Issue 7238, 26 October 1901, Page 2

AUSTRALIAN GEM STONES.

Considerable quantities of sapphires, rubies, emeralds and other gem stones have been found io Australia during the laßt few years (writes John Plummer, in an English contemporary), and although there have been comparatively few of commercial value, their abundance naturally leads to the assumption that in the near future discoveries of a superior class of stones will be made. In Now South Wales sapphires ara found in many places, mostly in alluvial deposits containing gold and tin j but it ia only in a few. instances that the stones possess sufficiently good colour to render them valuable as gems; the majority of the sapphires having a greenislvblue or bottlegreen tint, while most of thoHe which are pure blue by transmitted light are of such a deep shade that they appear almost black when seen by reflected light. Sapphires of indifferent quality are especially, numerous a. few miles to the east of Inverell, in the northern part of the State, so nvucli so that the name Sapphire has been given to the locality. Rubies are frequently met with, but specimens of the oriental, or true ruby, are somewhat rare. It is possible, however, that crystals of sufficient «&« and purity to be commercially valuable may y«t be. discovered. The "topaz ia found m jnany places in New 'South Wale« % especif ally in the northern elevated regions. Here, near Emmaville, floe colourkss transparent crystals were found associated with, emerald, beryl, fluorspar, mispickle, kaolin and tinstone in a pegmatite dyke traversing indurated claystones. Many of the topaaes haveX BEATJTIFDIi PALE BLUE COLOUB, and are of larjje size. Professor LiverEidge states that a portion of a large bluish'green crystal found at Mudgee, in the westero dis' tricts, weighed several pounds ; also that one found at Gundagai, in the Bouth, $i a pale blue^green tint, measured three by one and a half inches, and weighed Hop sdwt, while another pf a similar colour from Gulgong weighed 18oz avoirdupois. The New South Wales emerald mining in. dustry dates from W9Q, when a rich deposit was discovered at EmmariUe, and 2225 carats forwarded as a trial sh, ipnjent to London, some of the gems realisipg £4 per Q&rat. About 50,000 carats were obtained during the next two years, but the hardness of the matrix in which the emeralds were found proved a source of considerable difficulty, it being almost impossible to break down the rook without injuring and frequently destroying the stones. In this way, it is asserted, many of the finest and most valuable specimens have been lost. The somewhat inferior character of later shipments to London caused th«m to prove unremunerative, and during the next few years mining operations became suspended. Thtee have since been resumed, and it is anticipated that in due course deposits of richer quality will be reached. Turqvoisa has recently been discovered in the coaptal region sooth of Sydney. It occurs chiefly as tbio veins, from one.sixteenth to nearly one.quart«r of an inch in thickness in the joints oi the slate. The colour of most of the mineral hitherto found is not sufficient, ly good to render it marketable, being of a Muish-'gyeen instead of the sky-blue which, makes turquoise A HIGH^Y'PRIZgJ) OEM. Some of the stones, however, are of fair colour, and l«od encouragement to the hope that further prospecting may result in the discovery of more valuable material. Zircons of small size are extremely common in the auriferous and stanniferous gravels in different parts of the State, but large stones are compartively rare. The beaoh sands of the northern coast, which contain platinum and tin, are largely composed of minute grains or crystals of zircon. The largest specimens of this mineral are found in the neighbourhood of Hanging Rock (Nundle) ; they are colourless and transparent, and possess such a fine lustre that the goldminerc have frequently mistaken them for diamonds. Garnets also are of common ocouiTence in many parts of the State, and they vary in size from minute grains ot crystals of one inch or more in diameter ; stapes suitable for cutting and polishing 1 , as gems appear to be rare, and so far they have not been regarded as of commercial importance. Other stones found in New South Wales include the opal, amethyst, chrysolite, cairng6nn and onyx ; in fact, almost every kind of known g«m stone is believed to exist in the State, but the absence of surface indications acts as a check upon systematic prospecting.