Naturalis historia 37.61

37.61

adamas dissidet cum magnete in tantum, ut iuxta positus ferrum non patiatur abstrahi aut, si admotus magnes adprehenderit , rapiat atque auferat. adamas et venena vincit atque inrita facit et lymphationes abigit metusque vanos expellit a mente. ob id quidam eum ananciten vocavere. —Metrodorus Scepsius in eadem Germania Basilia insula nasci, in qua et sucinum, solus, quod equidem legerim, dicit et praefert Arabicis. quod esse falsum quis dubitet?

When, by good fortune, this stone does happen to be broken, it divides into fragments so minute as to be almost imperceptible. These particles are held in great request by engravers, who enclose them in iron, and are enabled thereby, with the greatest facility, to cut the very hardest substances known. So great is the antipathy borne by this stone to the magnet, that when placed near, it will not allow of its attracting iron; or if the magnet has already attracted the iron, it will seize the metal and drag it away from the other. Adamas, too, overcomes and neutralizes poisons, dispels delirium, and banishes groundless perturbations of the mind; hence it is that some have given it the name of "ananchites." Metrodorus of Scepsis is the only author, that I know of, who says that this stone is found also in Germany, and in the island of Basilia, where amber is found. He says, too, that this is preferable to the stone of Arabia; but can there be any doubt that his statement is incorrect?