As the price of pure silver has risen over the past few years, many jewelry makers have moved to less expensive variants with lower silver content to keep prices down while still delivering attractive pieces for clientele. It is our belief that customers should know what they are getting. As a result, we have put together a summary of common silver variants along with information about approximate silver content and a simple home test anyone can perform.
One of the most common “silver” materials for sale internationally is Tibet silver. Tibet silver is only a name, it does not guarantee any silver content. Typically, what we know as Tibet silver today, is the Chinese PAKTONG, or cupronickle or copper-nickle. Typically this material is 60% copper, 20% nickel and 20% zinc.[1]
What about other silvers?
- Genuine Bali silver is generally around 92.5% silver but some makers are lowering the silver content as silver prices rise.
- Genuine Thai Hill Tribe silver is around 95% but again, some makers are reducing the silver content.
- Some American Indians found that they could get a very inexpensive silver, a metal also known as German silver, or Nickel Silver. This material has been found throughout American Indian works since the 19th century, in everything from horse bridal decorations to wearable Jewelry art.[2] The German silver was developed in an effort to copy the Chinese cupronickle.
- Fine Silver is 99.9% pure silver.
- Sterling Silver is 92.5% pure silver and 7.5% other metals, often copper.
- Genuine Mexican silver has to be at least 90% pure silver and much of it is 92.5%.
- Britannia Silver is 95.85% pure silver with not more than 4.16% copper.
So what is a consumer to do? The name of the silver can provide an indication of the process and silver content. Silver content can also be established by specific gravity testing and simple chemical tests (chemical test not recommended in the kitchen). However, some research has turned up this quick and simple test that anyone can perform at home.
- Get a genuine Sterling Silver item and a Tibetan, Bali, or Mexican silver item.
- Wet the items – preferably with distilled water (because distilled water doesn’t have the contaminants found in tap water)
- Place the items on a plate.
- Cut a hard boiled egg in half (free range eggs have a higher sulfur content so they work better).
- Place half of an egg on the plate.
- Cover the plate with a glass dish or other solid, see-through cover and watch. The lower the silver content, the quicker it tarnishes.
Take the tarnished items and boil them in a dilute solution of sodium carbonate or bicarbonate (baking soda). Only the silver with at least 80% silver content will revert back to a white silver surface. It the item turns more of a salmon color, then its a high copper alloy. Items that have an appearance similar to stainless steel will be nickle silver or stainless.
Two things to observe to understand silver content of an item:
- Time it took to tarnish by comparing a known metal against an unknown. The color of the tarnish is another clue, as the lower the silver content, the quicker and blacker the tarnish, maybe even a greenish tinge.
- Color of the metal after the baking soda test.
Note: this test does not harm the metal. In fact the baking soda “test” is one method of cleaning and removing tarnish from silver.
[1] Tim McCreight, The Complete Metalsmith.
[2] Dubin, Lois Sherr. North American Indian Jewelry and Adornment: From Prehistory to the Present. New York: Harry N. Abrams, 1999. ISBN 0-8109-3689-5., p. 290-293.