Cosmetics And Gem Materials

(via The Journal of Gemmology, Vol. IX, No.8, October 1964) R Webster writes:

Chalcedony
The only case of possible attack by cosmetics on chalcedony was one referred to the writer some time ago, and for which, at the time, no decision was reached, particularly as the change seemed so fantastic. Here a lady’s signet ring, set (presumably) with a black onyx, was submitted for investigation. The story which came with the enquiry was that the black stone was originally red (cornelian or stained agate) and had turned black. The owner of the ring was said to be a hairdresser and it was questioned whether chemicals used for hair-treatment could have caused the change of color. No information was given as to the nature of the chemicals used, or the type of hair-dressing preparations used by this hair-dresser. The only question asked was whether such an occurrence had been encountered before. To the best of my knowledge it had not, or at least had not been reported, and the matter rested there.

However, intrigued by the effect which, presumably, had occurred with the stone in the lady’s ring, some experiments were carried out. A piece of cornelian, probably dyed agate, was immersed in a tube of 25% sodium sulphide and left for some time, after which it was removed and dried. No apparent effect was then noticed, but some time later, after the stone had lain on a shelf open to daylight, the stone was seen to have darkened, but admittedly did not turn black but to a very dark brown. The notion underlying this experiment was that as the color of cornelian was due to iron, the action of the sodium sulphide might produce the black ferrous sulphide (FeS).

To perform the second experiment a small piece was broken off from the blackened specimen and immersed in a 20-volume solution of hydrogen peroxide and left for twenty four hours. On the removal of the piece from the solution it was seen that it had returned to the original reddish color, that of cornelian. Another piece was broken off the darkened specimen and immersed in ordinary tap water in order to check whether the darkening was just surface deposit which could be washed off. No lightening took place even after three days immersion. Whether the hydrogen peroxide solution would return the color when other dyes were used is a matter for debate and further experiment.

To get further information the writer approached the technical staff of Golden Ltd, the makers and distributors of the hairdressing products of L’Oreal of Paris, who were good enough to submit specimens of cornelian to treatments with some of their products. These tests involved immersion in samples of Pastel and Progress cold-wave lotions, Ciloreal-skin-stain remover, and a number of basic chemicals used in the manufacturing of L’Oreal products, both for hair coloring and permanent waving. Tests were also carried out by the Golden technicians with a 10% sodium sulphide solution; and one stringent test was with a Pastel cold wave No.1 at a temperature of 75ºC for eight hours. On the return of the stones, in no single instance was any blackening of the stones noticed. Later, however, after the stones had been kept in a stone paper for a few months, two of the pieces did seem to have somewhat darkened in color, but they certainly had not turned black.

It is clear from the above that any change in the color of cornelian could only occur after prolonged treatment, as in the case of the hairdresser who could well be using cosmetic chemicals daily, and would anyway be of rare occurrence, and not an expensive item to replace, but it does illustrate what troubles can be encountered.

The objects of this article is to warn the jeweler that cosmetics, when incorrectly used, may have a deleterious effect on certain types of gem materials. This is no criticism of beauty preparations in themselves when they are used with common sense, but so often ladies are oblivious to the fact that they are wearing their jewelry when completing the final touches to their make-up; then the jeweler is challenged as to the resultant changes.