ORIGINAL CORRESPONDENCE. To the Editor of the New Zealander.

New Zealander, Volume 8, Issue 693, 4 December 1852, Page 3

ORIGINAL CORRESPONDENCE. To the Editor of the New Zealander.

Sir, —On reading the letter from the Secretary to the Society of Arts, Manufactures and Commerce, copied into your last number from the New Minister Government Gazette, it occurred to me, as the article " Corundum" is made special mention of, it would be well if our fellowcolonists who are employed at the Coroniandel gold diggings would preserve specimens of all stones, having a peculiar appearance, they *may meet with in the course of their labours, especially those having a crystalline structure. Let them carefully note the places where they have been found, and, should the finders themselves be ignorant of mineralogy, they can submit the specimens to a competent person for examination on their return to Auckland. Valuable minerals have often been discovered in this way. Now, as the conditions under which Corundum is found appear to be fulfilled in the Coromnndel district, I will give a short description of that mineral for the guidance of the diggers: — Corundum occurs in granitic rocks accompanied by magnetic iron; its crystalline form is mostly that of a six-sided prism, sometimes with its corners levelled; its colour is generally of a greyish or greenish tint, although it occasionally varies, being sometimes nearly colourless, reddish or brown, more rarely blue, yellow or black. But it is frequently found compact, having the appearance of a rough purplish coloured jasper, but of a granular texture. A splinter of Corundum will scratch quartz with ease. The sapphire, oriental ruby, and emery are varieties of Corundum; the two first 1 need scarcely say are valuable gems. The Museum which has lately been established in Auckland, might be made the means of imparting a knowledge of mineralogy to those desiroua of obtaining !t? and diroouns: tlie attention of Lnose who have opportunity and leisure to the deveiopement of our mineral resources,—l am, Sir, your obedient servant, G.M.M. Auckland, Dec, 2, 1852,