Siderit
Another name for the magnet.
Signs, Planetary: (See Astrology.) Silvester II., Pope, (Gerbert, died 1003): One of a number of popes who from the tenth century onwards were regarded as sorcerers. It was said-and the story probably emanated from the Gnostics who had been proscribed by the Church-that Gerbert had evoked a demon who obtained for him the papacy, and who further promised him that he should die only after he had celebrated High Mass in Jerusalem. One day, while he was saying mass in a Church in Rome, he felt suddenly ill, and remembering that he was in the Church of the Holy Cross in Jerusalem, he knew that the demon had played him a trick. Before he died, the chronicler continues, he confessed to his cardinals his compact with the devil. However, as Gerbert had been preceptor of two monarchs, and a friend of others, it is more likely that he owed his preference to one of these. He was one of the most learned men of his day, a proficient in mathematics, astronomy, and mechanics. He it was who introduced clocks, and some writers credit him with the invention of arithmetic as we now have it. It is not at all improbable that his scientific pursuits seemed to the ignorant to savour of magic. The technical language employed in his various studies might well have a sinister significance to the ignorant. The brazen head which William of Malmesbury speaks of as belonging to Silvester, and which answered questions in an oracular manner probably had its origin in a similar misinterpretation of scientific apparatus. But however that may be, there is no lack of picturesque detail in some of the stories told of him. By the aid of sorcery he is said to have discovered buried treasure and to have visited a marvellous underground palace, whose riches and splendour vanished at a touch. His very tomb was believed to possess the powers of sorcery, and to shed tears when one of the succeeding popes was about to die.