precious stones

   Lapidaries, i.e. treatises on the 'virtues' of precious and semi-precious stones, circulated throughout medieval and Renaissance Europe. Some writers dealt only with their supposed curative properties; others said they had a moral influence too, for example that amethyst prevents drunkenness, and sapphire cures anger and stupidity; the majority also listed magical powers, for example detecting poison, driving demons away, ensuring the favour of princes, etc. The power of the jewel could be enhanced by engraving it with planetary or zodiacal symbols, or with religious formulas such as Hebrew titles for God, names of angels, acronyms representing Scriptural phrases, etc. Many surviving medieval and Elizabethan rings and pendants prove that these principles were put into practice by those who could afford to do so. Those who could not, nevertheless knew about them at second hand, through popular manuals of magic such as The Secrets of Albertus Magnus, of the Vertues of Herbes, Stones, and certaine Beasts (1637). Unrelated but analogous beliefs have arisen in the 20th century, first as regards the luck of birthstones, and more recently as regards the healing properties and spiritual symbolism of crystals.