Dealing in pearls
The dealing in pearls is normally an entirely separate business from that of other gem stones, and for many years there “were a certain number of merchants, comparatively few, who used to handle almost the whole of the annual output of the Persian Gulf. But restricted production and sale since about the year 1925 have obliged most of these pearl dealers to handle other gems as well. The introduction of the cultured pearl had a temporarily depressing effect on the values of natural pearls, but here again, the realization by the public that the two kinds could be distinguished, generally without difficulty and always with certainty, led to a gradual recovery in prices. Moreover, the disappearance of the cultured pearl from almost all markets when Japan entered the war in 1941 led to a greater demand for the natural gem, the price of which has consequently risen once more. It still, however, falls far below that which was obtained during the boom years of about 1920, despite the comparatively small world’s pearl fishery.
The price of pearls is based on a unique method, and one that is not used with any other gem stone. Its origin is no doubt Eastern, but it is used by all pearl merchants in every part of the world, except when very small pearls are being considered. The pearl is first weighed in grains, and this weight is squared. The resultant figure, called the base, or one shilling base, is regarded as shillings. The base value of the pearl or pearls is then judged according to current market values, and the shilling base is then multiplied by this estimated base value and translated into dollars when needed.
For instance, a five grain pearl valued at 20/- (about $2.80) base is worth a total sum of $70 (£25). A ten grain pearl valued at this same base would be worth considerably more than twice the value of a five grain pearl, in fact, $280 (£100). Prices of pearls in the trade are always referred to by base, except seed pearls or very small pearls, and poor quality misshapen (baroque) pearls, which are priced by the carat.