Above two karats the prices are not much increased per karat, because of their not being as much in demand. Stones of five karats and upwards, being very slow to sell, at the present time can be bought at $175 to $200 per karat, of the same qualities as the two-karat stones quoted above. Very extra white perfect stones, when well cut, bring, when sold singly or few at a time, from 20 to 25 per cent more than the prices quoted. The lower grades of stones are generally sold in lots, and the sizes do not make much difference in price. The larger they are the less desirable, and oftentimes stones of from five to ten karats are sold cheaper than stones of one to two karats; the price depending upon the shade of color and skill in cutting. Lots of this description can be bought for from $75 to $90 per karat. If the tinge is a little more decided they will bring but $60 per karat. The yellow diamonds even ranging as high as ten to twenty karats bring about $45 per karat. Flawy stones bring from $15 to $35 per karat, according to their color, size, and brilliancy. Fine rough stones of assorted sizes, varying from three to ten karats, bring from $30 to $45 per karat according to their shape and perfection. Smaller sizes are reckoned in value from $15 to $20 per karat. Cheaper grades and off-colored crystals are sold as low as $8 to $12 per karat. The bort diamonds vary in value; those coming from Africa bring but $1.50 per karat, while the same variety found in Brazil bring $6. The carbon variety of the best sizes bring about $20 per karat. Fifteen years ago the same mineral could be bought for $2.50 per karat; while the Brazilian bort was quoted at $9. Of colored diamonds, those slightly tinged with various colors, especially the yellow and brown, were valued in London and Amsterdam, in 1872, as follows:-- Under 1 karat 30s. to £2 10s. per karat. 1 to 2 ” 40 ” 4 10 ” ” 2 ” 3 ” £3 ” 5 10 ” ” The following account of Cape of Good Hope diamonds which were sold by auction at Covent Garden, February, 1872, may interest the reader in comparison with other sales at various periods of time:-- One white rough diamond, 9¹⁄₂ karats, £60; one slightly off color, 7¹⁄₄ karats, £37; a curious cabinet specimen of native diamond in matrix, £14, one large rough gem, drop shape, 14¹⁄₂ karats, £42. Among the cut diamonds the following were sold: a magnificent brilliant, 8 karats, 430 guineas; a fine yellow brilliant of great lustre, 7¹⁄₂ karats, 140 guineas; a brilliant of great spread and good water, about 7¹⁄₂ karats, 140 guineas; a large, lustrous brilliant of fine color weighing about 7 karats, 480 guineas; a court tiara of five graduated brilliant stars, 185 guineas; a brilliant necklace of forty graduated collets, £300.