Page:A treatise on diamonds and precious stones including their history Natural and commercial.djvu/55

 that they are sold by weight. Diamonds free from flaws have generally a regular price: they are easily taken out of the setting, and a working jeweller would do it in a few minutes; but if the brilliants. are very thin it is the safest way to put them, fora few hours, in nitric acid, when they become loose by the acid dissolving a portion of the silver cramps that confine them.

and portraits set with brilliants are generally composed of thin Diamonds, which present a large surface.

fineness, as well as the weight of Diamonds, as before stated, must be considered in estimating their value. Suppose a half hoop ring to be composed of five stones, allow the centre one to weigh three grains; those next to it 24 grains each, and the others, 2 grains each: here would be three carats of Diamonds, which, if fine, would cost the retailer from £18