Book IV Sulphur, amber, Pliny's gems, jet, bitumen, naphtha, camphor, maltha, Samothracian gem, thracius stone, obsidianus stone Page 80



	68	DE NATURA FOSSILIUM

	made no reference to coal. Theophrastus writes that native coals are those earthy substances which we regard as varieties of stone and earth and which, for that reason, we call by a name formed from stone and coal. Certainly some are much harder than others. It is obvious that every writer should have given a reason for the selection and meaning of his name, for example, those who have called this native bitumen, earth, or have said that it is an earthy coal and those who call it stone or λι0ώδια coal because they regard coal as being soft and this material as being hard. For the same reason some have called a similar hard bitumen jet because they classify it as a stone. The Germans call it by a name composed of a corruption of the original name to which they have added the name for stone.⁶ Since it actually belongs to this genus a description of it will suffice. Jet, according to various writers, is black, tabular, quite light, inflammable and with an odor similar to bitumen. The most inflammable is the best. If sprinkled with water it will burn stronger but sprinkling with oil extinguishes the fire. Nicander writes that it is not consumed by fire either because bitumen burns continuously within the earth in many places or because the Magi, who use it in what they call divination, according to Pliny, deny that it is consumed if they so wish it for any reason. Serpents are driven away by its fumes. Having been warmed by rubbing it will pick up small light objects as does amber. It will not do this unless it has a natural brilliancy or has been polished. Solinus says that this property is limited to gemmy jet while Dioscorides, on the other hand, says that rough unpolished jet has the same property. Pliny writes that jet does not differ greatly from wood and since it is by nature tabular it has this type of fracture. It breaks with ease when dropped. The gem samothracia is seen to be nothing other than polished jet since Pliny writes that it has the same color, lightness and resemblance to wood. He writes, a black gem with a weight similar to that of wood is given the name of the island of Samothrace. Lapis thracius is identical with jet. According to Euax Maurus it is black. According to Nicander and Dioscorides when it is sprinkled with water it burns with a very clear flame and is entirely consumed the same as bitumen and when sprinkled with oil it will not burn. An unknown Greek writer states that when burned it has an odor similar to that of bitumen but so acrid and unpleasant that no serpent will remain near it. In addition, a follower of Nicander correctly observes that it is bitumen because it has hardened after the manner of a stone. Lapis obsidianus is the same as jet since it is very black; because it gives a shadowy reflection similar to the image in a mirror; and because small statues have been made from it. In fact these and other similar criteria are those by which jet is distinguished from stones. Moreover we know this concerning

	⁸ Agat stein or Aidstein.