Precious metals are our business. Sometimes we are asked by customers what our products are made of. Our answer is always sterling silver, Britannia silver or white gold, but what does this actually mean? All of these materials are precious metals and alloys of silver or gold. Pure precious metals are too soft for jewellery making purposes, so they are mixed with different proportions of another metal to improve their qualities.
Sterling Silver & Britannia Silver
Sterling silver is 92.5% pure silver, mixed with another metal to improve its durability. The most common metal to be added is copper, although other metals, such as germanium, zinc, platinum and more recently argentium have been used, with claims that argentium silver inhibits tarnishing.
Britannia Silver is 95% silver, so slightly softer than sterling silver, which enables a really good finish to be achieved when setting stones in a rubover setting.
Silver is sometimes given an extra coating of Rhodium, to maintain its shine, reduce tarnishing and reduce any allergic reactions.
Mexican Silver or Alpaca
This is an alloy of copper, tin, zinc and nickel, although due to high incidence of allergic reactions to nickel, there are strict controls concerning the use of nickel. It contains absolutely no silver and should not be confused with sterling silver, which originated in Mexico!
The most common different levels of gold purity are 9 carat (37.5%), 18 carat (75%) and 22 carat (91.6%), with 9 carat being the most hardwearing. When choosing rings to be worn together, such as engagement rings and wedding bands, it is worth bearing in mind that ideally all rings should be of the same purity, otherwise the softer metal will be worn away by the harder one.
To obtain true white gold, the other metal used is palladium, which is itself white in colour. This is the alloy that we stock at Amulet. Some jewellers use an alloy which is more yellow in colour, and then rhodium plate on top to achieve the silver finish. However if the item is subject to wear, then the rhodium will rub off and need to be recoated from time to time.