Testing a large stone
One should always test a large stone to ensure that it is genuine and not a synthetic material or a doublet. Stones set in jewelry or in backed metal mounts should be removed carefully—emerald is soft and brittle—since they cannot be judged fairly for weight or color when so presented. Poor quality emeralds, those of pale color and fissured, are difficult to sell at $5.60 (£2) a carat, so it must be remembered that there is a vast difference between the prices of inferior and fine quality stones.
Emeralds are comparatively light in weight, so their size should not be over-estimated if it is not possible to resort to direct weighing. Moreover, the brilliant cut is unusual with emeralds and diamond eternity rings; they are almost always trap cut if of any size. Repolishing often improves old stones, and it is sometimes advantageous to re-cut larger stones to obtain better proportions. Heat should not be applied to emeralds; in fact, all stones except the diamond uternity ringsshould first be taken out of their settings if it is necessary to solder or alter the mount in any way. And this needs the hand of a careful and skilful setter.