Sapphire
Sapphire is fit for the fingers of kings; it is resplendent and like the sky when free from clouds; there is no other stone which has greater virtue or beauty. Men call it Syrtites because it is found in the sand of Libya near the Syrtes. The best is that which is found in Turkey, for this is not translucent. It is of such great virtue that it is by right called the gem of all gems. It comforts the body and keeps its members whole; it overcomes envy and treachery, and it drives away fear. It frees a man from prison and looses heavy fetters; it is good for effecting reconciliation, and is better than any other stone for seeing in the water the signs which reveal things hitherto not known. As medicine it is valuable because it cools an internal fever; if a person dissolves it in milk it will cure bad diseases. It is good for the eyes, and for headache, and for disease of the tongue. He who carries it must be chaste.
Amethyst
The amethyst has a purple color, or sometimes is like violet or like drops of wine or like a rose. Some there are which turn almost white, others are like red wine mixed with water. From India it comes; it is easy to work, and it prevents intoxication. It would be precious if it were not so abundant, but it is commonplace since there is so much of it. There are five kinds.
Geratite
Geratite is black. It is of such a nature that if a man opens his mouth and puts the stone under his tongue he will divine what another person thinks of him, and can win any woman's devotion. This stone can be tried as follows: let a man anoint himself with milk and honey, go out into the sunshine where insects swarm, and if he has the stone in his mouth the insects will not attack him; if he removes the stone they will at once sting him.
Chelidonius
Chelidonius is a stone which one finds in the stomach of a swallow. It is not very beautiful, but it surpasses all the beautiful stones in usefulness. It is of ten sorts and of two colors—black and red. The red is good for the frenzy which seizes people who are moon-struck; it restores their sanity to madmen and cures those who are pining away. He who carries this stone will be a good orator and will be much beloved. One must carry it wrapped in linen cloth and suspended under the left arm. The black, if worn in the same way, aids a man to accomplish important things he has undertaken; it is also a help against the threats and rages of kings and princes. The water in which it is washed is helpful to diseased eyes. If wrapped in linen cloth of saffron tint, it drives away fever and restrains the humors which injure the body.