“We will make it our business to point out the methods of detecting these false stones, seeing that it is only proper to put luxury even on its guard against fraud.”
~Pliny the Elder
Naturalis Historia (AD 77–79)
A simulant is a natural or artificial material that imitates the appearance of a real gemstone without possessing its identical chemical or physical properties. In other words, a simulant is a fake.
Simulants have been around as long as gemstones, and they come in many forms. Thousands of years ago, the Egyptians pioneered the use of glass (i.e. paste) gemstones. Pliny the Elder (AD 23–79) mentions several techniques by which the unwary were fooled and suggests tests to prove the genuine article (Trans. Bostock and Riley, 1855):
“There is considerable difficulty in distinguishing genuine stones from false; the more so, as there has been discovered a method of transforming genuine stones of one kind into false stones of another. Sardonyx, for example, is imitated by cementing together three other precious stones, in such a way that no skill can detect the fraud; a black stone being used for the purpose, a white stone, and one of a vermilion colour, each of them, in its own way, a stone of high repute. Nay, even more than this, there are books in existence, the authors of which I forbear to name, which give instructions how to stain crystal in such a way as to imitate smaragdus [emerald] and other transparent stones, how to make sardonyx of sarda, and other gems in a similar manner.”
The Papyrus Graecus Holmiensis (c. AD 300), also known as the Stockholm Papyrus (Trans. E. R. Caley, 1926), contains many recipes for the creation of false gemstones including:
“Preparation of Carnelian. Dissolve alkanet in oil. After that, put in the blood of a pigeon, and fine Sinopian earth and a little vinegar in order that the blood does not coagulate. Place selenite [or some transparent stone] in it, close the vessel and place it amidst the dew for ten days. If you wish to make the stone very brilliant, arrange it so as to wrap it in horse hair, tie this on, and put it in the dye bath.
“Preparation of Emerald. Take and put so-called topaz stone in liquid alum and leave it there three days. Then remove it from this and put it in a small copper vessel in which you have placed pure unadulterated verdigris along with sharp vinegar. Put the cover upon the vessel, close up the cover, and gently keep a fire under the vessel with olive wood for six hours, otherwise the longer you maintain the fire, the better and deeper will the stone be—only, as I say, with a gentle fire. Cool and lift the stone out. Its condition will show whether it has become emerald. That is to say, you will observe that a green film has formed upon it. Let it become slowly cooled, however; if not, it soon breaks. Put oil in a small box-tree vessel many days beforehand so that the oil is purified and the product from it can be taken off. Put in the stone and leave it under cover seven days. On taking out you will have an emerald which resembles the natural ones.
“Preparation of Beryl. Tie crystal around with a hair and hang it in a pot along with the urine of a she-ass for three days, but the crystal is not permitted to touch the urine. The pot should be closed, however. Then place the pot over a gentle fire and you will find a very good beryl.”
Diamonds have also been simulated for centuries. Reference to diamond simulants and tests to determine their false nature can be found in ancient Indian texts. According to Tagore’s (1879) translation:
“Skillful lapidaries make use of iron, the ruby, the gomeda, the lapis lazuli, crystal and glass of various colors, in fabricating false diamonds; therefore, before buying diamonds, they should be first tested by a skillful judge of precious stones. There are three ways of testing a diamond; first, by mixing it with ashes; secondly, by rubbing; and thirdly, by whetting a weapon over it. A false diamond is reduced to powder by the first test, and wears away by the second and the third,–changes which can never be produced in real diamonds.”
In the past red gemstones labelled “carbuncle” or “granat” were actually a mixture of garnets, hyacinths, and rubies. In his (1652) Lapidary, or The History of Pretious [sic] Stones: With Cautions for the Undeceiving of all Those that Deal with Pretious [sic] Stones, Thomas Nicols informs us that some of these red stones were also fakes:
“Impostours have many frauds and deceits for adulterating this gemme; which frauds and deceits in the adulteration, together with the great difference of its severall species, make this gemme, saith Andreas Baccius, of greater difficultie than any other to be known.”
“If the owner of a garnet ring who was not an expert in precious stones wished to assure himself of the genuineness of his garnet, the following rather troublesome experiment was at his disposal. He was to disrobe, still wearing his ring, and then to have his body smeared with honey. This done, he was to lie down where flies or wasps were about. If in spite of the sweet temptation they failed to light on his body, this was a proof that the garnet was genuine, an added proof being that when he took off the garnet ring the insects would hasten to make up for lost time and suck up the honey.”
- Gemstone Treatments: An Historical Perspective
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