Book VI gems: diamond, emeralds, sapphire, topaz, chrysoberyl, carbuncle, jaspis Page 138



	126	DE NATURA FOSSILIUM

	Smaragdus transmits images as if it were glass and a piece of it was used by Nero when he watched gladiatorial combats. Concave gems are the best for focusing an image. These sooth eyes that have been strained but do not cure them according to Pliny. It does restore keen sight to eyes that see indistinctly as a result of strain. The gentle green of this gem is most soothing to the strained eyes of the gem engraver. Any lewd act is very dangerous to a smaragdus. If either a man or a woman wears this gem during cohabitation and it touches the flesh, even when set in a ring, it will be shattered.¹³ It combats epilepsy as though it were a deadly enemy until it either overcomes the lesser power of the disease or is overcome by a greater power. In the former case the stone remains whole and intact but in the latter case it is fractured into many small pieces. For this reason kings and priests suspend it from the necks of boys and wear it in rings in order to test whether it will have the power to expel this horrible disease. Theophrastus writes that the smaragdus from Cyprus can solder gold the same as borax. These two minerals have a similar color and are seen to have similar properties.¹⁴ From the above remarks one may know which smaragdi are the best yet some judge the quality of these gems solely by their place of origin. Judged in this manner the Scythian stones are the best, the Bactrian second, the Egyptian third, the Ethiopian stones of pure uniform color fourth and the Cyprian fifth. The other stones are worthless.¹⁵ Beryllus is also green. It is found in India; in Arabia according to Strabo; in Phoenicia in veins of ophites according to Dionysius Afer; and accordihg to Pliny it was found in our own world at one time around the Black Sea. The color is green but lighter than that of smaragdus and often the fulgor¹⁶ is of another color. For this reason there are eight species of beryllus. The most highly prized has the pure green color of the sea and takes its name from this. The next species is called chrysoberyllus because ¹³ There is a superstition today that if a wife wears an emerald and her husband is unfaithful to her the stone will turn white. ¹⁴ See under chrysocolla. Agricola recognizes two species of this mineral, the natural which includes malachite, chrysocolla, etc., and the artificial which is borax. He is speaking here of borax which is white and confusing it with green malachite and chrysocolla. ¹⁶ Several green minerals are included under smaragdus. This is due in great part to confused descriptions and the lack of comparison of the minerals described by the different writers. Primarily smaragdus was the modern emerald, a variety of beryl. The following characteristics must refer to the emerald,—the gem is not brilliant but transparent; found in Egypt and Ethiopia; the Scythian stones are the best; contains many flaws; the green color is not uniform and may grade into white. The gem from Cyprus which is described as half smaragdus and half jaspis is probably red and green jasper. The gem that appears to die of old age and can have the color improved by placing it in wine or oil probably refers to turquois. The smaragdus of Theophrastus from Cyprus was probably chrysocolla. ¹⁶ Agricola uses the term fulgor in a sense which cannot be translated directly in many instances. Literally fulgor is brilliancy but it is meaningless in this association since color is not a quality of brilliancy. A possible translation is "flash."