MANUFACTURED DIAMONDS.

New Zealand Herald, Volume XLV, Issue 13707, 25 March 1908, Page 7

MANUFACTURED DIAMONDS.

M. LEMOINE'S EOKMULA.

TO REMAIN LOCKED UP.

By Telegraph.—Press Association.—Copyright

(Received March 24, 11.53 p.m.) London", March 1. A fresh application made on behalf of the French Government at the Bow-street Police Court to secure the release from the London bank of the envelope containing the recipe for the manufacture of diamonds was refused, as M. Lemoine, who is charged with fraud in this connection, strenuously objected. Diamond lias been defined as a peculiar form or variety of the chemical element carbon —a very peculiar form, most people will say who remember that charcoal and lamp-black are the- common form of carbon. That one and the sane unchangeable chemical element can exist as an amorphous black lump or powder, and, ulso, without addition or loss of chemical constituents, as the clearest, hardest, and most brilliant of crystals, is a paradox. The late Professor Moissan, of Paris, obtained artificial diamonds by suddenly cooling the iron in which carbon was dissolved by plunging the crucible into water. _ The outer shell of iron cools and forms 9 tightlyclosed shell enclosing ths still liquid core. As this core cools it tends to expand, and thus produces an enormous pressure. The melted carbon cooling under this pressure assumes the crystalline colourless form known as diamond. 'There is good reason to believe that diamonds are formed, or have been formed, in association with metallic iron in a similar way, on a large scale, in great depths of the earth's crust, and are shot up to the surface with other debris in the volcanic steam mud, which is the "blue ground" in which the gems are found in the South African mines. The largest diamond in the world is the Cullinan, which weighs 210z., and was recently presented to the King by the people of the Transvaal, where it was found.