Diamond.—It would be curious if many traditions of occult power had not centralized about this precious stone, and a bare enumeration only of its virtues is possible in the present place. It prevails against poison, plague, panic, insomnia, charms and enchantments. It soothes anger, reconciles husbands and wives. When it has been consecrated under the planet Mars and engraved with an image of that deity, it renders the wearer invincible, whence it naturally inspires courage. Worn round the neck, it insures safe childbirth. In some other ways, it seems to have been regarded as unpropitious.
Emerald.—If ground into powder, this stone was supposed to cure dysentery and the bites of venomous animals. There is a chance that those who wear it will not be subject to epilepsy. It also strengthens memory and maintains chastity.
Heliotrope.—The stone bearing the name, in common with a beautiful and well-known flower, should be sought by the curious, as it renders the wearer invisible. But it is unknown in these days.
Hematite or Bloodstone.—Valuable for its power in incantations, against the sorcery of the evil eye, and to cement the bonds of friendship among male persons.
Hyacinth.—This also is a preservative against the plague, which was a common scourge in the old days, and was therefore an especial concern of occult medicine and its substitutes. The hyacinth was also a cure for dropsy.
Jade.—This is another stone which protects against venomous beasts.
Jasper.—This stone is noticeable chiefly as a favorite gem on which magical signs were engraved, so that they might be worn as amulets. But it also preserved the wearer from poisonous bites.
Linurgas or Lapis Lineus.—A stone of ancient repute which would turn white if enveloped in a linen cloth, and the use of it would then prove beneficial in projects of magic. But it has been decided that the gem itself is fabulous, not to speak of the properties attributed thereto.
Onyx.—When engraved with the head of a camel, this stone procured evil dreams. It may have been used against enemies.
Opal.—The malefic influence which is sometimes attributed to this jewel, by which it has almost come to be regarded as unfortunate in the world of gems, has little authority in past traditions. It acted rather like a cordial to the heart of the wearer, was a safeguard against poison and contagion transmitted in the atmosphere; it served to raise the spirits and was valuable in affections of the eye.