

[ This article is written in personna. ]

Concerning Gemstones

In the name of ALLAH,
The Merciful, the Compassionate,
Who is sufficient unto us,
upon Whom we depend and Whose aid we invoke,
by Whose mercy this work may serve the people of the Six Kingdoms
(for it is for that, that it is intended);
and it is written "Upon ALLAH we rely,"
and from Him also do we invoke the peace
on all of His prophets and worshippers,
who are sincere in obeying Him,
for there is no strength and no power
except with ALLAH,
The Exalted, the Almighty!

The Philosopher wrote concerning gemstones, and Theophrastos, and Pliny, and after them many wise men in the East and the West, that is to say among the Arabs, the Persians, and the Moors, as for instance Ibn al-Jezzar and Abu Ali ibn Sina, and also some philosophers of the Franks have written about stones. Many attribute magical properties to certain gemstones, and according to others these stones have such properties but they are not magical, being according to the nature of the stone. And Allah alone knoweth all.

It is my purpose to tell a little of how gems are cut, and into what shapes, and what gems are used among the different peoples of the earth; it is my hope thus to be of service to the people of the Six Kingdoms, most especially to those who would know what sorts of jewelry it is most fitting to give as gifts to friends of other nations, and also to such as themselves desire to work with gemstones.

Concerning their Shaping

There are two ways I know of, that gems may be worked to the desired shape. The first is told by Theophilus, a Frankish craftsman; these are his words:

Rock crystal is water hardened into ice, which is then hardened through many years into stone. It is cut and polished in this way. Take some chaser's pitch, about which we spoke above, and put it into the fire until it melts. Then cement the crystal with it to a long piece of wood of comparable thickness. When it is cold, rub it with both hands on a piece of hard sandstone, adding water, until it takes on the shape you want to give it, then on another stone of the same kind but finer and smoother until it becomes completely smooth. Now take a flat, smooth lead plate and on it put a moistened tile (which has been abraded [to dust] with saliva on a hard hone) and polish the crystal until it becomes brilliant. Lastly, put some tile dust moistened with saliva on a goat skin that is neither blackened nor greased, stretched on a piece of wood and fastened on the underside with nails. Rub on this until it is completely clear.

In the same book, he also tells of another way of polishing gems:

In the same way onyx, beryl, emerald, jasper, chalcedony, and the other precious stones are cut, ground and polished. A very fine powder is also made from fragments of crystal. This is mixed with water and put on a smooth flat piece of lime wood and the same stones are rubbed on it and polished. Hyacinth, which is harder, is polished in the following way. There is a stone called emery, which is crushed until it is like sand, then placed on a smooth copper plate and mixed with water and the hyacinth is shaped by rubbing on this. The washings which run off should be carefully collected in a clean basin and allowed to stand overnight. On the following day the water should be entirely removed and the powder dried. Afterwards put it on a smooth flat limewood board, wet it with saliva, and polish the hyacinth on it. Gems made of glass are also ground and polished in the same way as rock crystal.

With regard to hard stones, it should be said that sapphire and ruby are very hard, and also certain sorts of the stone called asterias, that has a star in it; these would certainly require the use of emery. The stone chrysoberyl, that some call chryselectrum, is golden or pale green and has a line shining in it like the eye of a cat, and it is very hard, and so is the golden stone that Pliny calls chrysolithus, but that is called topazos by later writers, and also the stone balas, that some say is a sort of ruby. It may be that all of these would require emery for their polishing, but I cannot say for I have not polished stones in this fashion.

The other way in which stones may be shaped is on a wheel, and it is done so for the most part in civilized lands. The wheel may be of stone, or of wood or metal or wax and have on it powdered emery or other such stuff mixed with water. Tripoli is also used for polishing stones. Sometimes the wheel is turned by a bow; the string wraps around the shaft of the wheel and the craftsman turns the wheel by moving the bow back and forth with one hand, while with the other he shapes the stone against the turning wheel. I have heard also of wheels turned by the feet, and even of great stone wheels turned by water, but those I have not seen.

The stone adamant is so hard that it is said that it cannot be shaped or polished, but it is set in its natural shape, sometimes flat, sometimes like two pyramids joined at their bases, and then it is set with a sharp point upright, and will write on glass. Others say that adamant may be polished, or even shaped, by rubbing one against another, but this I have not seen or done. Also I have heard that certain men have the art of striking the stone so that it breaks in two pieces, the break as smooth as if it had been cut with a saw and then polished.

Concerning the sawing of stones, Theophilus writes:

If you want to cut up a piece of crystal, fix four wooden pegs on a bench so that the crystal lies firmly between them. They should be spaced so that each of the pairs is so closely fitted above and below that a saw can just be drawn between them and cannot be deflected anywhere. Then insert an iron saw and throw on sharp sand mixed with water. Have two men stand there to draw the saw and to throw on sand mixed with water unceasingly. This should be continued until the crystal is cut into two parts; then rub and polish them as above.

Also concerning the engraving of stones, this may be done in several ways. In the simplest, a small sapphire or adamant is fixed to the end of a rod and with it designs are cut into the stone. Then again the rod may be rotated with a bow; this is called a bow drill. One can use in the same way a drill of wood, and a paste of water mixed with emery or some other such stuff. Also the stone can be engraved against a turning wheel. All of these methods have been used in the countries of the East and the West and among the Romans. Theophilus says little about engraving stones and I do not know how it is done among the Franks, or if they have the skill for such work.

Sometimes when a stone is being shaped, the lapidary discovers a flaw, or some foreign matter within the stone. If the stone is of little price he may elect to grind it down on the wheel until the flaw is gone. To do this with a stone of great value would be costly, as the weight would be reduced by the grinding away of much that was perfect and whole in order to remove a little that was imperfect; no man of sense would so waste his money or his patron's. Instead it is common practice to make a cut in the surface of the stone where it is flawed, removing the flaw and polishing the sides of the cut. It is for this reason that one often sees a stone with such polished cuts in the top of it. And as for emeralds, those of great size are never flawless, and so the flaws are permitted to remain.

Concerning their Shapes

Gemstones are for the most part cut in one of two ways. Either the stone is cut with a rounded top and bottom (I have heard that the Franks call such a stone a cabochon, for that it resembles in their eyes a small cabbage) or it is polished all over, keeping the natural shape of the stone that no weight be lost (and this is of special importance in stones of great price, for they are valued in large part by their weight) and a hole drilled through it. Stones of the first of these two sorts are set in jewelry, held by a bezel or by claws; the second sort can be strung on a necklace, or affixed to a piece of jewelry by a wire through the hole, as is done among the Romans. And the stones cut in the first way have sometimes their backs hollowed instead of domed, and then polished, that the color may be more clearly seen, and this is done especially with garnets. Also in setting stones often a foil, of gold or of some other metal, is put behind the stone to brighten it and improve its color. Among certain Frankish peoples, and especially the English, it was of old the custom to cut and polish garnets in thin slices, and set them upon a foil of gold marked like a game board, and done so fine that there might be eighty lines to the inch. I have seen this work myself and it is most skillfully done, so that it is a wonder to me that it was done by men who know nothing of the Prophet (on him be the peace and the blessings of Allah!) or of the philosophers.

There are other ways in which stones are cut, but these are for the most part new fashons, and I doubt whether a man of good judgment ought to follow them. Some take stones that are to be drilled and cover them all over with small flat surfaces, polished, called facets, taking care always to follow the shape of the stone (if it be a valuable one) and waste as little weight as may be. Others, who have stones that are to be set and not drilled, instead of cutting them rounded, put facets of the same sort on them. This I have seen done in two ways. With some stones (it may be those of greatest price) there are many small facets, following the shape of the stone as with drilled stones, and having no special pattern.

With others there are only a few; the top may be one facet, and the four sides each flat, and perhaps as many as eight facets on the bottom side. All this work is done in Persia, and I have seen the stones; I do not know what the fashion may be among the Franks, but doubtless they will in time copy it, for stones cut in such ways sparkle in the sunlight, and are pleasing to the taste of simple people. Another way in which stones are cut is to take the form of the stone as it comes from the earth, and this for some (most especially emeralds, but also rock crystal and others) is, as it were, a solid of Euclid, with its surfaces plane, and to polish these surfaces, and then drill the stone. It may be that from this ancient practice the idea of faceting arose. As for how stones are set, that would be a matter for a treatise on jewelry, and that (if Allah is willing!) I shall do at another time.

Concerning the Different Peoples

All stones were known to the Romans in the old days when they ruled both Romes, the old and the new, for Pliny wrote of them all. In these times still the Romans know many stones, and whether any known to the old Romans are lost to them I cannot say. Certain stones they favor most especially, and these are emeralds and pearls, also garnet and crystal they make much use of. They use other stones also, but the especial skill of their jewelers is with enamels, and none in the East or the West is more skilled in that craft.

The Franks in the old times, and especially those of England, who were very great jewelers, used agate and almandine (that is a kind of garnet), also amethyst and amber and jet, the last two being found on the coasts of England. Also I have heard that onyx and crystal were known to them. It may be that they knew other stones also, but that I cannot say.

In these days the Franks know the use of many stones. But often for one stone they use many names, and at other times one name signifies stones that are wholly different. Thus the ruby and the ballas ruby and the garnet are all at times called by the one name: carbuncle, that signifies a red stone. And their philosophers cannot agree among themselves concerning the naming of stones.

The Northmen are a people who live north of the Franks; I have seen a little of their jewlery, and it is very fine. I have heard that they use garnets and crystal and also amber and walrus ivory, but I think they must know the use of other stones also, for many of them are pirates and raid very far. They have even raided in the West, in Spain. It is said that the fighting there was very bloody; many women, children, and Northmen were killed. Also some of them take service with the Romans and doubtless bring treasures from New Rome, which they call the Great City.

The Irish are a people that live at the end of the world, beyond the English. It is said they use amber and crystal, and make fine jewelry.

As to the peoples of the East and the West, that is the Persians, the Arabs, and the Moors, they know all stones and make use of them.

Thanks be to ALLAH, the Merciful, the Compassionate, that it has been granted to me to complete this treatise to serve the people of the Six Kingdoms, as is the will of ALLAH, the One, the Only.

Notes & Bibliography

The above description of medieval lapidary technology is in part conjectural, based on what is known about classical technology and about "traditional" (i.e., modern pre-industrial) Persian techniques. In general, techniques are described as "rumors", etc., if it is reasonably certain that they existed prior to A.D. 1600, and possible (but not certain) that they existed in the author's period: the 11th or 12th century. Water-driven lapidary wheels are an example.

There is no way to be certain that a particular natural gemstone was not used in a given historical period. Even if all modern sources are in areas which were then inaccessible, some other deposit might have been known in the past and either lost or exhausted. Similarly, even if no jewelry using the stone exists from the period, that might mean only that it was sufficiently rare that no pieces survived. But where no positive evidence exists, neither in contemporary writings nor in surviving pieces, that a particular stone was used, and where the presently known sources would in the past have been difficult of access, one may reasonably suppose that it was either totally unknown or at least rare-and in the latter case probably confused with some more common stone that it resembled. Stones which I believe would not have been known in the Middle Ages have been omitted from the list of medieval gemstones appended to these notes. Such stones are:

Alexandrite: First known discovery was in the 19th century, but it is found in Ceylon, which was an important source of gem rough in period. Black Opal: First known discovery was in Australia. Jade: Although prehistoric jade weapons are known from Europe, and although jade was used extensively in China from very early times, it does not seem to have been known as a distinct stone in Europe until the 16th century, when it was introduced from South America by the Spanish. In the Middle East it probably became known about the 13th century as a result of the Mongol conquest of Persia. Individual objects containing jade from earlier periods have been reported, but according to Ogden all of the specimens he checked turned out to be other green stones. Jade would presumably have been misidentified as some other green stone, possibly jasper, plasma, or chrysoprase. Labradorite: A novelty when it was discovered in Labrador in 1780. Deposits also exist in Norway, Finland, and Madagascar, but were apparently unknown until recently. Star Diopside: While it might be one of the stones referred to as "asterias," there seems to be no evidence that it was known prior to the 20th century. Tanzanite: African in origin, apparently first discovered in the 20th century. Its color is the result of heat treatment. Tiger Eye: The main sources are in southern Africa and were discovered in the 19th century-it was regarded as a novelty at the time. Tourmaline: Gem tourmaline was introduced to Europe by the Dutch (from Ceylon) in 1703. Since it occurs in areas which were mined for other gems from an early period, it seems likely that individual stones were known earlier but misidentified. Ogden describes one definite example from classical antiquity and two others of uncertain date, one of which may be medieval.

Facetting. The widespread belief that facetting originated in the 15th century appears to be an error, caused by considering only European stones. Persian facetted stones of the sorts described above appear to date back at least to the 12th century; there is an example (a facetted sapphire in a gold ring) in the Walters collection in Baltimore. In the 15th century facetted stones began to replace cabochons in western European jewelry. The table cut and the earliest forms of the rose cut appear to have originated about 1500, the systematic rose cut, the Mazarin, and the early forms of the brilliant cut in the early 17th century. Beads with polished flat surfaces were made in classical antiquity.

Diamonds. Diamond crystals are normally either platelets or octahedral; the latter, set point up, is the point naif or writing diamond, the form commonly used before the invention of the table cut. During the Middle Ages and Renaissance diamonds were sometimes backed with black foil; Cellini recommends tinting the back surfaces with lamp black, backing the stones with a reflector, or both. Large irregular stones, at least in the East, were "facetted" in such a way as to minimize weight loss-covered with facets conforming to the original shape of the stone. Neither procedure gave anything like the effect of modern cuts. It was only in the 17th century that the diamond began to become the most important gemstone.

Names of Stones. In the list below, stones are given by their modern names; other names are also listed, usually in their Latin form (from Pliny). Nomenclature was neither consistent nor stable over time; in many cases a writer such as Albertus had to guess which of the stones he knew corresponded to particular stones listed by Pliny. Chrysolite and (golden) topaz exchanged names sometime during the Middle Ages. Sapphire was originally the name of the stone now called lapis lazuli. Modern names first documented after A.D. 1600 are marked with an asterisk; names in brackets probably referred to several gems; a question mark designates an uncertain identification:

almandine (a variety of garnet)
amber [succinas] [chryselectrum]
amazonstone*, eumentres
chrysoberyl, cat's eye [chryselectrum]
chrysolite (exchanged names with topaz during the Middle Ages)
citrine [chryselectrum] [topasion]
diamond [adamant]
emerald [smaragdus]
garnet [carbunculus]
heltiotrope, bloodstone
jet, kacabre [gagates] [succinus]
lapis lazuli [sapphire (in classical antiquity, and to some degree in the Middle Ages)] zamech, ultramarine
malachite [smaragdus]
moonstone [silenites][asterias?]
mother of pearl, celontes [silenites]
opal, exacontalitus, pantherus
pearl, margarita
rock crystal, crystallus,iris [beryllus]
rose quartz
ruby [carbunculus][jaqut (Arabic)]
sapphire [hyacinth] [adamas] [jaqut (Arabic)]
spinel, balas ruby [carbunculus]
star garnet [asterias?]
star ruby [asterias?]
star sapphire [asterias?]
topaz (the yellow variety of topaz exchanged names with chrysolite during the Middle Ages
sunstone (probably known in Roman and medieval times, but identification not certain)
zircon, jargoon, jacinth [hyacinth], [lycurium] zargun (Persian)

Select Bibliography

Albertus Magnus. Book of Minerals. Tr. by Dorothy Wyckoff. Oxford 1967.

Ball, Sydney H. A Roman Book on Precious Stones. Los Angeles 1950.

Cellini, Benvenuto. Treatise on Goldsmithing and Sculpture. Tr. by C. R. Ashbee, N. Y. 1967.

Heniger, Ernst A. & Jean. The Great Book of Jewels. Lausanne 1974.

Jessup, Ronald. Anglo-Saxon Jewellery. Aylesbury 1974.

Lucas, A. Ancient Egyptian Materials and Industries. London 1962.

Ogden, Jack, Jewellery of the Ancient World. Rizzoli, N.Y., 1982.

Theophilus. On Divers Arts. Tr. by J. Hawthorne and C. Smith. Chicago 1976.

Wulff, Hans E. The Traditional Crafts of Persia. Cambridge (Massachusetts) 1966.

[Originally printed in Tournaments Illuminated No. 47, Summer 1978. Artwork by Alia bint Ulek ibn el Kharish]

Webbed by Gregory Blount of Isenfir