CHAP. 54.—PEARLS; HOW THEY ARE PRODUCED, AND WHERE.
The first rank then, and the very highest position among all valuables, belongs to the pearl. It is the Indian Ocean that principally sends them to us: and thus have they, amid those monsters so frightful and so huge which we have already described,1 to cross so many seas, and to traverse such lengthened tracts of land, scorched by the ardent rays of a burning sun: and then, too, by the Indians themselves they have to be sought in certain islands, and those but very few in number. The most productive of pearls is the island of Taprobane, and that of Stoidis, as already mentioned2 in the description of the world; Perimula,3 also, a promontory of India. But those are most highly valued which are found in the vicinity of Arabia,4 in the Persian Gulf, which forms a part of the Red Sea.The origin5 and production of the shell-fish is not very different from that of the shell of the oyster. When the genial season of the year6 exercises its influence on the animal, it is said that, yawning, as it were, it opens its shell, and so receives a kind of dew, by means of which it becomes impregnated; and that at length it gives birth, after many struggles, to the burden of its shell, in the shape of pearls, which vary according to the quality of the dew. If this has been in a perfectly pure state when it flowed into the shell, then the pearl produced is white and brilliant, but if it was turbid, then the pearl is of a clouded colour also; if the sky should happen to have been lowering when it was generated, the pearl will be of a pallid colour; from all which it is quite evident that the quality of the pearl depends much more upon a calm state of the heavens than of the sea, and hence it is that it contracts a cloudy hue, or a limpid appearance, according to the degree of serenity of the sky in the morning.
If, again, the fish is satiated in a reasonable time, then the pearl produced increases rapidly in size. If it should happen to lighten at the time, the animal shuts its shell, and the pearl is diminished in size in proportion to the fast that the animal has to endure: but if, in addition to this, it should thun- der7 as well, then it becomes alarmed, and closing the shell in an instant, produces what is known as a physema,8 or pearl-bubble, filled with air, and bearing a resemblance to a pearl, but in appearance only, as it is quite empty, and devoid of body; these bubbles are formed by the abortion of the shellfish. Those which are produced in a perfectly healthy state consist of numerous layers, so that they may be looked upon, not inappropriately, as similar in conformation to the callosities on the body of an animal; and they should therefore be cleaned by experienced hands. It is wonderful, however, that they should be influenced thus pleasurably by the state of the heavens, seeing that by the action of the sun the pearls are turned of a red colour, and lose all their whiteness, just like the human body. Hence it is that those which keep their whiteness the best are the pelagie, or main-sea pearls, which lie at too great a depth to be reached by the sun's rays; and yet these even turn yellow with age, grow dull and wrinkled, and it is only in their youth that they possess that brilliancy which is so highly esteemed in them. When old, too, the coat grows thick, and they adhere to the shell,9 from which they can only be separated with the assistance of a file.10 Those pearls which have one surface flat and the other spherical, opposite to the plane side, are for that reason called tympania,11 or tambour-pearls. I have seen pearls still adhering to the shell; for which reason the shells were used as boxes for unguents. In addition to these facts, we may remark that the pearl is soft12 in the water, but that it grows hard the instant it is taken out.
