Why and When to Use the Test

This test can be used on objects which are primarily gold, even if alloyed with silver and/or copper. If the method of manufacture likely involved heating the gold at least near to the melting point, then the metal may be suited to testing. It can be used after an object has passed other non-destructive tests and examinations, such as composition, method of manufacture, and weathering/wear patterns. Samples might also be submitted if there was any questionable result from a previous test, or if one would, perhaps, simply wish to contribute (at the $2700+ cost) to the general database.

To date, the scientific testing of most metal cannot provide an actual calendar age. Gold is one of the few exceptions. A technique known as Uranium, Thorium, 4-Helium (U, Th, 4-He) Analysis has the potential to date the last time gold was heated above a critical temperature, such as during the manufacture of an object.

Advantages & Disadvantages

The application of this test to art and artifacts is in its infancy. As such, at present, there are more cons that pros, but that balance should change as more samples are tested, and advances are made.

Advantages

1) On suitable samples, it can provide excellent evidence of age, just by itself. Used in conjunction with other examinations, it can provide evidence of authenticity of a gold object.
2) It can provide a date on objects as young as approximately 150 years in age, and as old as several thousand years. In the future, as the margin of error for the technique is improved, this should help identify copies made in antiquity, which are of historic interest, from modern forgeries.

Disadvantages

1) It is a destructive test, which currently requires a 30mg sample.
2) It is expensive (over $2700 at today’s exchange rates).
3) It requires a minimum of approximately two months to obtain results, and often takes significantly longer. It can actually take up to a year to get into the testing rotation.
4) The margin of error is currently quite large (generally around 50%, although closer to 30% has been achieved with some samples). We have had two samples with a little over a 30% margin of error, but one sample with 66%.
5) The database is relatively small.
6) It is not suited for use on some types of gold, but the parameters for consistently identifying that type of gold, before testing, have not yet been established.
7) Unsuitable samples yield inconclusive results, though modern material appears to yield an appropriately modern result. Unfortunately those samples yielding “inconclusive,” results still cost $2700 plus.
8) The sample is destroyed in testing, thus as the method is improved, an additional sample would be required for objects which previously tested as inconclusive.
9) There is currently only one team, which consists of scientists in different cities and different institutions, performing this testing.

Rich red cabochon garnets nestled in bezels of gold and surrounded by delicate twisted wire adorn this petite gold flask found in northwestern China. This exquisite work of art, purportedly 1st century, is equipped with tiny loops from which the flask could be hung. The purpose of such vessels is uncertain. They might have served as perfume bottles. The Kazakhs are reputed to have used small flasks of gold or silver to hold precious spices for smelling, while artifacts recovered in Cyprus have included a necklace, equipped with a tiny gold flask which may once have contained perfume. A close comparable to our little treasure was found in Taurid Province, in the Crimea, and is attributed to the Sarmatians of the 1st century.

Currently accepted positioning of this style of “Kolti”