D I A 



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D I A 



whence its great brilliancy is 

 derived. Its lustre is brilliant 

 adamantine ; fracture conch oidal. 

 Neither acids nor alkalies produce 

 any effect upon it. The diamond 

 is hard in the highest degree, and 

 scratches all other known minerals. 

 Specific gravity from 3 '5 to 3*6. 

 It burns when heated to 14 of 

 "Wedgwood's pyrometer, a point 

 just below that at which silver 

 fuses. It is the natural edge of 

 the diamond only that has the 

 property of cutting glass, all arti- 

 ficially formed edges will only tear 

 or scratch it. Diamonds are found 

 of nearly every shade of colour ; 

 those which are colourless are 

 deemed the most valuable. The 

 weight and value of diamonds is 

 estimated in carats, one carat being 

 equal to four grains, and the 

 difference between the price of one 

 diamond and another, all other 

 matters being equal, is as the 

 squares of their respective weights, 

 thus the value of three diamonds of 

 one, two and three carats weight, 

 is as one, four, and nine. To 

 estimate the value of a wrought 

 diamond, ascertain its weight in 

 carats, multiply this by two, then 

 multiply this product into itself, 

 and lastly multiply this latter sum 

 by 2. Thus a wrought diamond 

 of one carat is worth 8, one of 

 two carats is worth 32, one of 

 three carats 72, one of four carats 

 128; and so on. Zireon is some- 

 times substituted for diamond. 

 The largest diamond known is 

 said to be that which belonged 

 to the late Emperor of the Brazils ; 

 it is uncut, and weighs 1680 carats, 

 or 11 ounces 96 grains. This 

 magnificent gem would be worth, 

 supposing the table of rates to be 

 applicable to stones above a certain 

 size, 5,645,000, but the highest 

 price that has ever been given for 

 a single diamond is 150,000. A 

 diamond in the possession of the 



Great Mogul is of the size of half a 

 hen's egg. The Pitt diamond, 

 now the property of the king of the 

 French, was sold for 100,000.; it 

 weighs 136 carats, or nearly one 

 ounce. 



Brazil and Hindostan are the 

 localities where diamonds are prin- 

 cipally obtained. Those of Brazil 

 are generally less large, but of the 

 finest water. Diamonds are cut 

 and manufactured into what are 

 termed brilliants and rose-diamonds, 

 The former being mostly made out 

 of octahedral crystals, the latter 

 from the spheroidal varieties. In 

 the formation of either of these, so 

 much is cut away, that the weight 

 of the polished gem does not exceed 

 the half of the rough crystal from 

 which it was wrought, wherefore 

 the value by weight of a cut 

 diamond is twice that of a rough 

 diamond, exclusive of the expence 

 of workmanship. 



DI'AMOND SHAPED. Leaves are so 

 called when approaching to a 

 square, having four sides, of which 

 those opposite are equal : the four 

 angles are generally, two obtuse, 

 and two acute. 



DIA'NCHOBA. A genus of attached 

 inequivalved bivalves; the attached 

 valve having an opening instead of 

 a beak, the other beaked and eared ; 

 the hinge toothless. 



DrA'NDRiA. (from Sis, and dvrjp, Gr.) 

 The second class of plants in Lin- 

 naBus' artificial arrangement; they 

 have two stamens. This is a very 

 numerous class, consisting of three 

 orders, and comprehends all herma- 

 phrodite flowers having two sta- 

 mens. 



DIA'JSTDRIAN. Having two stamens ; 

 belonging to the class Diandria. 



DIA'PHANOUS. (Suxfiavf)?, pellucid, 

 from Suxfraivw, Gr. diaphane, Fr.) 

 Which may be seen through ; 

 transparent; pellucid. That which 

 allows a passage to the rays of 

 light. 



