About the Effects of Precious Stones on the Human Spirit

"There are," says Bacon, in his "Sylva Sylvarum," "many things that operate upon the spirits of man by secret sympathy and antipathy. That precious stones have virtues in the wearing, has been anciently and generally received, and they are said to produce several effects. So much is true, that gems have fine spirits, as appears by their splendour, and therefore may operate, by consent, on the spirits of men, to strengthen and exhilarate them. The best stones for this purpose are the diamond, the emerald, the hyacinth, and the yellow topaz. As for their particular properties, no credit can be given to them. But it is manifest that light, above all things, rejoices the spirits of men; and, probably, varied light has the same effect, with greater novelty; which may be one cause why precious stones exhilarate."