406 pliny's natural history. [Book XXXVII. 



only, and to very few of them. Such was the name given to 

 a nodosity of gold,^ sometimes, though but rarely, found in the 

 mines, in close proximity with gold, and only there to be 

 found, it was thought. The ancients supposed that adamas 

 was only to be discovered in the mines of ^thiopia,^ between 

 the Temple of Mercury and the island of Meroe ; and they 

 have informed us that it was never larger than a cucumber- 

 seed, or differing at all from it in colour. 



At the present day, for the first time, there are no less than 

 six different varieties of it recognized. The Indian adamas is 

 found, not in a stratum of gold, but in a substance of a 

 kindred nature to crystal ; which it closely resembles in its 

 transparency and its highly polished hexangular and hexahe- 

 dral^ form. In shape it is turbinated, running to a point at 

 either extremity, and closely resembling, marvellous to think 

 of, two cones united at the base. In size, too, it is as large 

 even as a hazel-nut. Eesembling that of India, is the adamas* 

 of Arabia, which is found in a similar bed, but not so large in 

 size. Other varieties have a pallid hue like that of silver, 

 and are only to be found in the midst of gold of the very 

 finest quality. These stones are tested upon the anvil, and 

 will resist the blow to such an extent, as to make the iron re- 

 bound and the very anvil split asunder.^ Indeed its hai'dness 

 is beyond all expression, while at the same time it quite sets 

 fire at defiance ' and is incapable of being heated ; owing to 



specular iron ore, emery, and other substances of rather high degrees of 

 hardness, which cannot now be identified. It is doubtful whether Pliny 

 had any acquaintance with the real diamond." — System of Mineralogy, Art. 

 Diamond. We may also add, from the same authority, that the method of 

 polishing diamonds was first discovered in 1456, by Louis Berquen, a citizen 

 of Bruges, previous to which time the diamond was only known in its 

 native uncut state. 



2 This statement cannot apply to the "diamond" as known tons, 

 though occasionally grains of gold have been found in the vicinity of the 

 diamond. 



3 Ajasson is of opinion that the Ethiopia here mentioned is in reality 

 India, and that the "Temple of Mercury" means the Brahmaloka, or Tem- 

 ple of Brahma. 



* The diamond, as known to us, is octahedral. 



5 Though found in comparative abundance in India, the diamond is not 

 found in Arabia. 



^ This is not the case with the diamond ; for on being struck under such 

 circumstances, it will break. 



■^ In reality, the diamond will burn, and, at a temperature of 14° Wedge- 

 wood, is wholly consumed, producing carbonic acid gas. 



