Minerals and Metals in Ancient India v2.c43.s3.t1.12

v2.c43.s3.t1.12

While Br. Saṃ. and RP fixed the price of diamond on the basis of weight only, AM (42 and 49-52) suggested that volume should also be considered. Ideally, a piece of diamond having the volume of a barley grain should have the weight of a grain of rice (AM, 42). Evidently, specific gravity was recognised as an important consideration. AM and subsequent literatures (GP, 68.38 and 47; MM, 139) have created confusion by commenting that lighter diamonds are necessarily better and hence more valuable. Agastimata or AM (49-52) suggested that the specific gravity of diamond could vary within the range — 75 + 25 per cent; this is ‘pure imagination’ in the words of Finot. The comment in *AM* 50: *tripādam tarate toye*, i.e., a diamond floats on water when it weighs three quarters less than the ideal mass for the same volume’, is very useful since it implies *Agastimata’s* opinion that diamond is four times denser than water, or that its specific gravity is 4.0 (the true value is 3.52). When it is stated that heavier pieces are impure and hence less valuable, what is implied is contamination of diamond with a heavy mineral such as zircon (sp. gr. average 4.68). That a diamond piece having lower weight per unit volume or specific gravily should fetch more price (*AM*, 49-52) was a preposterous suggestion, because such a piece would also be grossly impure. (Sarma, 1984: 50-53) The text in *AM*, 50, quoted before, was seriously misunderstood, and *Garuḍa Purāṇa* (68.38) even commented that a good piece of diamond should float in water!