¶ Second treatise of the second book concerning named

stones and their virtues. First chapter

concerning stones beginning with A.

Let us set forth the names of the principal stones and their virtues according to what has come down to us either through experience or through the writings of authorities. We will not, however, report everything said about them, because it does not benefit science. For natural science is not simply about accepting stories, but about inquiring into the causes of natural things. In order to follow a more suitable order for the Latin language, we shall proceed according to the order of the alphabet, following the names of the stones and their virtues in the manner that is customary for doctors describing simple medicines. In the first chapter, therefore, starting with "A," nine stones famous among the philosophers are found: namely, asbestos original: "abeston", absinthus, diamond original: "adamas", agate original: "agathes", alabandine, alectorius, amandine, amethyst, and androsmanta.

Abeston, otherwise called asbestos

Asbestos original: "abeston" is iron-colored and is found mostly in Arabia. Its wonderful power is said to be manifest in the temples of the gods, for once it is lit, it can hardly ever be extinguished. This is because it has the nature of a downy substance called "salamander’s feathers" original: "pluma salamandre," a medieval term for fibrous asbestos, which was believed to be the wool of the fire-dwelling salamander, which contains a small amount of oily, inseparable moisture that nourishes the fire kindled within it.

Adamas, commonly called diamond

The diamond original: "adamas", as we mentioned above, is a very hard stone, somewhat darker than crystal, yet of a bright and shining color. It is so solid that it is softened or dissolved neither by fire nor by iron. It is, however, softened and dissolved by the blood and flesh of a goat—especially if the goat has drunk wine and eaten parsley or mountain-parsley original: "silermontanum" for some time beforehand. This is because such a goat's blood is also effective for breaking the stone in the bladder of those suffering from the stone calculo. This stone also dissolves lead original: "soluit... plumbo", which seems quite wonderful, due to the large amount of quicksilver mercury that is within it. This stone penetrates iron and all other gems except for the steel in which it is held. It does not, however, attract iron—despite what some have falsely claimed—because that property belongs to its place of origin. The largest quantity of this stone found is the size of a hazelnut. It is born in Arabia and Cyprus for the most part, but the Cyprian kind is softer and darker. And what seems wonderful to many is that when this stone is placed over a magnet, it "binds" the magnet and does not permit it to attract iron.

Virtues of the diamond

Its greatest power is manifest when it is set in gold, silver, or steel. The mages say that when tied to the left arm, it is effective against enemies, insanity original: "insantā," likely "insaniam", wild beasts, fierce men, disputes, and brawls, and against poisons and the attacks of phantoms and incubi demons believed to trouble sleepers. Some call this stone "adamantine," and some even lie by saying it attracts iron.

Absinthus

Absinthus is a type of gem, black in color with red streaks and sometimes small spots. Its virtue seems to imitate that of asbestos; for absinthus remains hot for seven days or longer for the same reason given for the asbestos stone.

Four kinds of agate

Agate original: "agathes" is a black stone with white veins. Within this species, another type is found that is similar to coral. A third kind is born mostly on the island of Crete, which has yellow veins in black. The fourth kind is Indian, which is variegated as if sprinkled with drops of blood.

Virtues of the first kind

The first kind is suitable for the forms carved into stones; for this reason, many stones featuring the carved heads of kings are black. When placed at the head of a sleeper, it is said to show many dream-visions.

Virtues of the Cretan agate

The third kind, which is the Cretan one, makes one overcome dangers and confers strength to the body, as Avicenna says. It makes one graceful and pleasing—as Evax, King of the Arabs, said—and persuasive, of a good complexion, and eloquent, and it protects one against adversity. The Indian kind nourishes the sight and is effective against thirst and poison; when it is burned, it is very fragrant.

Virtues of Alabandine

Alabandine is so named from the place where it is mostly produced—that is, from Ephesus, which is called Alabandia by another name. It has a shining redness and is a clear stone, almost like the sardonyx original: "sardinus".

Alectorius

Alectorius is a gem called the "cock-stone" original: "lapis galli". It is a shining white, similar to dark crystal. It is extracted from the stomach of a rooster after it has lived more than four years; some say it is extracted after nine years and is better then, being taken from a decrepit rooster. The largest size found is close to that of a bean.

Virtues of the alectorius

Its virtue is to excite passion original: "venerem", and to make one a pleasing, constant victor and a discreet person. It grants the faculty of oratory, reconciles friends, and when held under the tongue, it extinguishes or represses thirst; this last property has been proven by experience.

Virtue of the Amandine

The amandine is a gem of various colors. Evax says that it either extinguishes or represses all poison, makes one overcome adversaries, and grants the understanding of prophecy and the interpretation of dreams, and even of riddles original: "enigmatum".

Amethyst

The amethyst is a very common and well-known gem; it is purple in color and somewhat darkly transparent. Many variations are found in this species, but five are most noted, distinguished by their levels of darkness. This species is born in India. It is the best for carving because it is less hard than others.

Virtues of the amethyst

It works against drunkenness, as Aaron says; it makes one vigilant, represses evil thoughts, and confers a good understanding of stable things.

Virtue of the Androsmanta

Androsmanta original: "andromanta" is a stone of a silvery color, which is mostly born in the Red Sea. It is square like a die original: "tessera" and hard like a diamond. it has power against fury and easy agitation of the mind, as well as against sadness and heaviness.