Stones weighed before use in jewelery
Stones of importance are weighed before being used in jewelry, and conversely an exact weight can be determined only if a stone is unset, or unmounted. In many instances, it is not practicable to unset stones when a quick valuation is required, and in considering diamonds, there are certain calculators on the market which give a fairly close idea of weight. One is a small sheet of plastic material, of convenient pocket size, through which a series of numbered and graduated holes have been punched. Each hole represents the weight of a round diamond which fits exactly into the hole.
Another idea is the Moe diamond weight gauge. Here, the greatest length and width of the stone are measured by a graduated pair of calipers, and each reading is listed in a small book of tables supplied, which gives the weight of the diamond corresponding to the two readings. There are other diamond gauges on the market which are basically the same as the Moe gauge, and modifications allow a finer reading with the calipers and consequently greater accuracy. It must be remembered that these instruments and booklets of tables do not apply to stones other than diamond. But both of these devices leave room for error, although the latter is the more accurate of the two.