Industrial Applications of the Diamond [antikvár]

Introduction to the diamond While this book has been produced as an aid to the use of diamond in an ever increasing variety of applications, it was thought that some general information on diamonds would not be out of place as an introduction. So many myths and legends have come down through the centuries that it is hard to separate fact from fiction, but even the legends serve to show that long before science had proved the pre-eminence of diamond as the hardest product of nature this had been known to the ancients. Pliny, in the first century a.d., records the method of testing a true diamond, which was that if this were placed on an anvil and struck with a hammer, both hammer and anvil would shatter but the stone would remain intact. He also refers to the source of diamonds as being a remote and inaccessible valley somewhere in the East: eagles swallowed some of the stones when feeding in the valley and they were then recovered elsewhere after the birds had flown out. Other qualities than hardness and beauty were attributed to good stones; they were worn by warrior princes because their qualities could be transferred to the wearer and they were reputed to guard the holder against poison and mental sickness. Pliny's reference to a valley in the East had, at that time, some basis of truth in that India then, and for several centuries afterwards, was the main source of diamond supply, and the mines of Golconda became invested with a reputation of almost boundless riches. The standard of weight, the carat, is thought to originate in those early days. In the Mediterranean countries and part of the Orient there grew fruit trees whose seeds or 'carats' were remarkably uniform in weight and size, and were used as the basis of small weight for trading purposes. Barley grains were used in European countries for similar transactions.