ROMANCE OF A DIAMOND.

Hauraki Plains Gazette, Volume XXXIX, Issue 5223, 6 January 1928, Page 4

ROMANCE OF A DIAMOND.

FORMATION OF THE CRYSTALS. IMPORTANCE OF CUTTING. Deep down in’ the bowels of; the earth, buried beneath hundreds of miles of molten rock, there lie huge masses of iron, heated to enormous temperatures, and impregnated with carbon." The terrific pressure of the rock above has compressed the carbon and iron with inconceivable force, and then, after some volcanic upheaval, they are flung up in layers nearer the earth’s surface, where during some thousands of years, they slowly .cool. In consequence of this the; dissolved carbon separates out into fluid globules, and as these gradually qool they harden into diamond crystals. These crystals are generally perfectly regular in form, which proves that they have crystalised out from a liquid, and, further, the fact that they very often burst or explode when they are brought to the surface shows the enormous pressure to which they have been subjected (says a contributor to the Edinburgh Weekly Scotsman). It is, then, on sites, of old volcanoes that diamonds are dug up or discovered by man. The volcanoes have been swept away by the. winds and rains of countless age& but there still remain volcanic ducts or “pipes” of blue clay, which go down for miles into the earth, and in them, long after the rocks in which they ’were; embedded have crumbled away liei the diamonds, indestiuctible and unchanged by time and temperatures. In beds of streams and alluvial soils, the debris of washed-out volcanoes, they are, also found. When diamonds’ are first found they are rough, unattractive pebbles, and are straightway shipped for polishing and cutting to the diamond mills of Antwerp and Amsterdam. Only in these mills do they know the v ; tal secrets of successful cutting; jealously guarded secrets handed down to them from their -ancestors, the, Portuguese Jews, who fled from persecution in their native; land, bringing their crafft with them. Tiny saws with minute diamond teeth are used to cleave the stones, and they are polished with diamond dust and oil against a revolving wheel. The- slightest mistake; of a cutter may cause a stone to be ruined; a badly cut facet will “leak the light,” and render the stone dull and lifeless instead of making it flash like; fire from every angle. And alt though the diamond is the hardest substance known, it is also very brittle ; two stones will even splinter against each ptlieA’. It is not the size of a, diamond so much as its brilliance that matters, and thus big stones have often increased in value on being recut, although diminished in size. Tire largest diamond ever found was. the Cullinan diamond, weighing 3025 carats. This, stone, which was se,en a long way off winking like a star from, the face of a. mine, was insured at once for £500,000. It now forms part of the Crown jewels.