The jewelry store must decide if it is going to try to sell the customer a well cut stone or a larger carat, poorly cut stone for the same price. This is a dilemma for dealers to consider. From a fair business standpoint it is important to explain to the customer why certain stones are sold for less per carat. Explaining the difference between a fine stone and a lumpy one to the customer is wise because, they will spread the knowledge to others. This will give the fine stones more credibility. People cannot make informed choice without professional, inside knowledge.



Sometimes the rough stones to be cut are thin in shape, or in cases where they have been cleaved or sawn to thin-shaped pieces, a lumpy stone cannot be fashioned well, on account of the loss of weight that would result. It is also not practical to make brilliants out of this type of material. There remains a lot of overspread stone on the market today. An overspread stone is known as a fish eye. Fish eyes are very undesirable stones, and should only be sold when a buyer wants a lot a diamond without a lot of money. The seller also owes the buyer a valid explanation of the matter at hand.

When an overspread stone is less exaggerated, however, the brilliant may be a very desirable stone. This type of stone is usually more desirable than a lumpy one. A slightly overspread stone will have a far greater effect that a lumpy one. If a finely made stone is placed next to a slightly overspread one it will shame it. Slightly overspread stones will appear weak at a little distance, but a finely made stone will still appear sharp and radiant. Overspread stones will also appear flawed when inspected through a glass.

Another common fault in make arises from the fact that more weight can be saved by not cutting a stone perfectly round. Most stones appear round enough when mounted to deceive the average eye. People would be surprised at the large number of stones that would fail, on accurate measurements of true roundness. If a diamonds lack of roundness is detectable, than the value of the stone is considerably reduced. Fancy shaped stones usually lack somewhat in brilliancy. A common rule is that the less round a stone is, the less brilliant the stone will be.

Dealers can use a few simple measurements to test a diamonds brilliance, while a few others can use their eye to obtain accurate results. One who is an expert in the business may be able to tell a diamonds brilliance at a glance, but when it comes to if the stone is finely made, some kind of measurement may be needed.

When measuring a diamond the spread should not quite be twice the thickness. 5 to 3 is nearly the correct proportions. According to the brilliant measurements, a 20 inch spread should measure about 12 inches in thickness. Second of all the position of the girdle should be nearly one third of the thickness. Third of all, the width of the table should be about four-tenths that of the stone. It will then very nearly equal the length of each of the principal top facets.

In general, all the facets on a stone should be alike in size and shape. Tiny facets are at times added to stones to finish off the surface. This is not a big defect but it does count against the stone a bit. This type of stone is worth more than a smaller one, but less than one of the same weight that is cut perfectly.

When purchasing a diamond, the girdle should be especially scrutinized. If the girdle is too thick, than a consumer has to pay for weight that is useless. Cutters do not want to leave the girdle unpolished because the gray edge may be reflected within the stone. Gray reflection within a diamond would hurt the color and brilliancy. The best of stones have either a knife-edge girdle, or one that is polished.

Commercial stones seldom have either. Of the diamonds with polished girdles some have tiny facets polished on them, while others have a curved polished surface. Optically the tiny facets are preferred, as curving surfaces do not give as sharp of reflections.