100 On Precious Stones. 



distinct in their crystallographic features. With regard to 

 the price of diamonds, I have copied the following from the 

 most recent work I could obtain — Bristow's Glossary of 

 Mineralogy (1861) — " Diamonds are weighed in carats (151 \ 

 " of which make one ounce troy) of 3.16 grains each. The 

 " medium value of a diamond when rough is £2, if of one carat 

 " weight ; and the value of diamonds of greater weight is 

 " estimated by multiplying the square of their weight in 

 " carats by two, which gives their value in pounds sterling. 

 " Example : — To find the weight of a rough diamond two 

 " carats in weight — the square of the weight 2 x 2=4 ; this 

 " multiplied by 2=4 x 2 =£8, the value of a diamond of 

 " two carats." " A polished diamond of the purest water, 

 " well cut and free from flaws, is worth £8 ; above that 

 " weight, the value is calculated by multiplying the square 

 " of the weight in carats by eight. Thus : — The value of a 

 "polished diamond of two carats — 2 x 2 x 8 =£32 ; the 

 " value of a polished stone of three carats — 3 x 3 x 8= £72, 

 "and so on." — Bristow, page 110. The following informa- 

 tion is taken from the works of Dr. L. Feuchtwanger, New 

 York, 1859 : — " Diamonds are found in talcose chlorite schist 

 " and in a breccia, consisting of ferruginous clay, quartz peb- 

 " bles, sand and oxide of iron fragments ; and also in a 

 " secondary bed, accompanied by gold, platinum, topaz, 

 " beryl, tourmaline, kyanite, amatoze, spinelle, corundum, 

 "and garnet. The rocks in which diamonds have been 

 " recently found consist of the itacolumite, a micaceous sand- 

 " stone, accompanied by mica-schist, accidentally traversed by 

 " quartz veins. The gold, diamonds, and other fine stones 

 " are always imbedded in the lower part of the alluvium.'' 

 Speaking of Brazil, he says, "Experience has shown the 

 " richest localities to be in Curranlinho, Datas, Mendanho, 

 " &c, where the alluvial soil is from eight to twenty feet 

 " thick, and is composed almost entirely of silicious sand, 

 " strongly coloured by argillaceous iron, which forms a species 

 " of cement of pebbles of quartz, milky quartz, and itacolu- 

 " mite, which form a coarse pudding stone, called cascalho, 

 " and which is considered by the diamond-washers a sure 

 " sign of the diamond." — Pp. 188, 189. I travelled last year 

 over a vast area of formations of the above characters. I 

 allude to the district in which the diamonds have been 

 found ; it stretches from the foot of the Beechworth hills to 

 Chiltern, and further ; and in even more strongly 

 marked features between Chiltern and Rutherglen. The 



