Monday 26 November 2012

Checking Purity of Silver Jewellery

When buying silver jewellery, you have to ask the seller how much silver is in the piece as jewellery metal. Unlike in the case of gold jewellery hallmarking in silver is treated with a kid glove. Though there are legal teeth enforcing this for international trade, domestic street jewellers shy away from the practice of hallmarking due to the cost factor. Nevertheless, if you ask them, most jewellers or their sales assistants would oblige by giving you the percentage of silver that went into the article. This is what we call as purity of silver.

The purity of silver, is determined by a Metric system that takes into account the Millesimal Fineness of the main metal used in a piece of jewellery. Basically this denotes purity of the main metal as parts per thousand of the mass of the alloy. Such a purity can be conveyed in three forms. One is to express it as a percentage of the mass of alloy say 99.9%; another way is to say it in number as 999; or in decimal form as 0.999. The decimal representation is also supplemented with the common name in which it is popularly known. For example 0.999 is added with the tag “fine silver”.

The fine silver is pure silver that is much malleable and ductile shining with the lustre and brightness comparable to gold. Yet it is too brittle and breaks and bends while on the production table. Hence, it is necessary to add external metals as alloys to give fine silver strength and hardness and other features necessary to make durable jewellery. There are several combinations in which such alloys can be made. Still a common rule applies: in order for a piece of jewellery to be sold as silver jewellery it must contain at-least 50% silver as the main metal. In certain countries legislation provides a legal minimum for silver in jewellery. For example in the USA, unless it contains 925 silver it cannot be marketed as silver jewellery. Elsewhere jewellers have more elbow room. They turn out pieces with varying percentage of silver in it. Here are few of the most commonplace ones:

1. 925 Silver: Alternatively known as ‘sterling silver” this type contains 925 silver per thousand. By and large, sterling silver is toasted as the standard in many countries including USA and UK. Most jewellers have pleasure in fabricating eye-pleasing 925 jewellery articles using different metals as alloys adding up to 75 parts per thousand. An interesting feature of alloying is that sometimes the resultant material carries the name of the major alloy used there in addition to silver. When silver 925 is alloyed with germanium it is referred to as “Argentum silver”; likewise when Palladium is the major alloy used in an article it goes as “Palladium silver”

2. 935 Silver: Used more in hand-made jewellery 935 silver contains that amount of silver per thousand and an alloy of 65 per thousand. This type of silver is more amenable for intricate carving and exquisite form of gem & jewellery

3. 958 Silver: Alternatively known as “Britannica silver” this type contains 958 silver per thousand with the remaining as alloy metals. Notably, 958 comes out well in thin and soft pieces such as chains

4. 950 Silver: Though the silver content is restricted to 950 per thousand, this type is most popular in France and Mexico where once upon a time this was the silver standard in coins in the respective countries

5. 900 Silver: Once the silver standard for coins in USA, 900 silver is popularly known as “coin silver” amongst the jewellers. However, it does not restrict the name coin silver being used for an alloy containing less than 900 per thousand. Exercise care when dealing with silver jewellery marked as coin silver grade. It is better to see the hallmarking in addition to the name coin silver in such piece of silver jewellery.

Muthu Ashraff

Business Adviser

Mobile: +94 777 265677

E-mail: cosmicgems@gmail.com

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