BROKEN DIAMONDS

Nelson Evening Mail, Volume LIII, Issue 72, 26 March 1919, Page 8

BROKEN DIAMONDS

MYSTERY OF NATURE. * , In an article in the Scientific Amets' can on the diamonds' of thr* Khnberlfef mines. Dr. J. R. Sutton disdussess origin of the numerous broken £rag» ments of u.amond found in that One hypothesis current oh the subject is that these ■ fragments owe their' con- - dition to violent, eruptive 'outbursts which shattered the ,!rocks in they occur. Another common* belief'is that certain- classes of fte* - quently break spontaneously. One ahthority states that light brown, sradky diamonds often craik on exposure ;td the diy air, but they will remain ’intacfc ' if kept in a moist place. In accordance with this notion-there is - of ' South African - -diamonds being, sent , to England inside potatoes. _ -r >. Crookes, in hia. Kimberley ".Lecture, seems to attribute* the fractures to- the sudden lowering of pressure in,the apace • surrounding diamonds, and sp ea ks of consequent explosion. Dr. Sutton says has met plenty of people heard of the bursting of smoky/dm-’ monds, but none - who ever wfneßeed this phenomenon with tfyeir Oym^-eyes. This idea of the bursting. of■ diamonds is of high antiquity. Albortus Magpjw says that a diamond immersed in - the fresh, warm blood of a go§t will. burst, —especially if the animat sad ; : previously browsed. on parsley or drunk, veins 1 ** Pliny vouchsafes a similar nbUon. ’ Dr, Sutton believes that. In a .'majority of cases, one breaking of diamonds has been due to the energy exerted .by the mineral inclusions which.they so often t contain. These are most frequently gati ne</, but sometimes zircon, ilmenite, iroA pyrites, and possibly chrysolite . Tl*| thermal expansion of nearly #ll crystal«f > except those of the beryl family, at or.. dinaa-v temperatures, is much greater . thruT'that of-the'diamond. ■ If.the, Bintt is true under plutonic conditioiis of hen and temperature, differences in 'ufe of expansion and contraction o\. * mond and its inclusion woul- • - ‘ for the shattering.