Approximate value of different gemstones
We have indicated in a previous chapter the approximate values of many different varieties of gem stones, and such values will have more meaning if one is able to judge qualities, which involves the recognition of faults and the appreciation of the merits of a given specimen. It is important to remember what is considered the best color and quality of the various varieties. Diamond is probably the most popular gem stone and the one most widely bought by the public, so we will add some further remarks on what constitutes a good stone.
In diamonds, we look for absence of color, since all color is due to minute impurities. Pure white is therefore considered perfection, but in reality, such stones are rare. The tints of color which one almost always sees are usually yellow or brown, and they are faint, passing to white by very fine graduations. Practice in detecting such different shades is necessary; stones should be viewed in a good north light, unobstructed, with no colored surface near so that light is reflected on to the stone. The morning is the best time to look at stones to see their true color, and dull and dark days should be avoided. Artificial light may give a false impression. It is almost impossible to carry color in one’s mind for the purpose of comparison, but judging in the same surroundings helps. This is one reason why stone merchants always like to buy in their own offices. But these ideal conditions are seldom present, and one should learn to judge stones in less favorable circumstances.