Portal logo
Login/Register
Bactrian Gold Treasure from Afghanistan, coming soon....
/gemstones/streeter-precious-stones/page_068 - 2
 

Sec. II, Ch. 1: The Diamond

Sec. II, Ch. 1: The Diamond Page of 366 Sec. II, Ch. 1: The Diamond Text size:minus plus Restore normal size   Mail page  Print this page
54
The Diamond.
Rundle & Bridge, for a sum which gave him a large profit. Long before Wollaston's time, however, there must have been many students of Precious Stones who were familiar with the cleavage of the Diamond. Thus De Boot, writing in 1609, tells us that he knew a physician who boasted that he could " divide a Diamond into small scales like a piece of talc." The fracture of the Diamond, apart from its cleavage, is conchoidal, and here and there the stone is liable to split off in fragments.
Among the physical properties of the Diamond that of hardness is pre-eminent ; a quality in which it so ex­ceeds all other bodies that it can penetrate them without being itself even scratched. In consequence of its excess­ive hardness it was formerly only possible to polish it partially, by rubbing it against another rough Diamond—a process which is known as " bruting." In early times there existed so exaggerated an idea of its extraordinary hard­ness that it was said a Diamond could not be broken by a hammer on an anvil, and that it was far easier to strike the anvil into the earth than to break the Diamond. This will account for the loss of many Diamonds in antiquity, as it was the absurd practice to place them upon the anvil to test their genuineness. Through this ignorance many a regal gem has been shattered and so lost to the world. It was, of course, only the brittleness of the stone which was really tested by the hammer, and not its hardness, which is a very different quality.
Pliny gives a detailed account of the Diamond in his " Natural History," xxxvii., 15. As translated by old Dr. Holland, he says : " The most valuable thing on earth is the Diamond, known only to kings, and to them im­perfectly. ... It is only engendered in the finest gold.....Six different kinds are known. Among
Sec. II, Ch. 1: The Diamond Page of 366 Sec. II, Ch. 1: The Diamond
Table Of Contents bullet Annotate/ Highlight
Streeter: Precious Stones and Gems
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page