Knowing & Measuring Gold Purity - Gold Karat

Measure purity of Gold – Gold Jewellery & gold product’s purity is measured and described in Karats, and it is a common notion that the higher the Karat, the more pure & expensive the gold will be. Let us understand what does Karat means? What is the significance of the fine imprint on the gold bars and coins?

Understanding Karat
A Karat is a measurement that indicates the proportion of gold alloy out of the 24 parts, i.e. 18K gold is 18/24 parts gold. The Karat defines the fineness of the gold (jewellery). The word Karat is from the same source as carat but came to refer to the fineness of gold: one karat is equal to 1/24th part of pure gold in an alloy. This fineness represents the weight of the fine metal that contains in proportion to the overall weight, including alloyed metals and any other impurities.

“Karats” are used in gold whereas a “Carat” is used to measure the size of the gemstones such as Diamonds. With gold, a karat is a fractional measure of purity for gold alloys, measured per 24 parts whole. Pure gold which has not been mixed with any other metals is the highest possible karat i.e. 24 karat (24k) gold.

Gold in its pure state is rarely used for jewellery purposes because of its softness, malleability and delicate tendency to break. Hence, to make a fine piece of jewellery, usually, 18K or 22K gold is used i.e. it is alloyed with base metals for use in jewellery, altering its malleability, colour and other properties.

Which Karat Marks as Its Best?
Gold in its pure form i.e. 24 karat gold is the highest possible number in a pure state and is often mixed with a few other metals for creating alloys which is more strong and comparatively more preferred for everyday wear in jewellery. The more an alloy is mixed with pure gold, the less gold there is hence, the lower the number of Karats.

Gold is often mixed with other metals such as either with Silver, Copper, Zinc or palladium to create different colours of gold such as rose gold, and white gold. The traditional karats used in gold jewellery number from pure gold at 24k, 22k, 18k, 14k or 10k.

Gold conversion chart

Higher the Karat, Higher the Quality of Gold?

To put it accurately, the answer is no. Though 24K is the purest form of gold, it does not derive or bring us to a conclusion that the higher the Karat, the higher the quality of gold will be available. The essence of the statement is that, there is more gold in it, hence it is more valuable. The 24 Karat Gold, being pure in its nature and form, is rarely used in making jewellery as it is highly fragile and can be easily damaged. The Gold which is blended with more alloys is stronger and is comparatively preferred more for jewellery purposes because lower the Karat, the making of jewellery is more durable.

For jewellery making, the most common used Karat is 18 Karat gold as it is generally the most sought-after gold, for example: the lower the karats in a ring, the stronger it will be. 18 Karat gold means that 18 out of 24 (3/4) parts of the piece are pure gold, a relatively high number. The one-quarter which is not gold would be made up of other alloys, which makes jewellery more durable, easy and better for regular wear.

The lower the number of Karat, the lesser will be the purity of gold and hence making it more affordable, suitable and durable for regular usage. You can also measure the purity of gold with the following methods.

Significance of Hallmark & Stamp!

While there is a possibility to come across certain piece of gold which are not stamped with purity, especially jewellery, will come with stamp to what we commonly regard as “Hallmark”. “Hallmark” is the symbol for any particular piece of jewellery as authentic, certified, original and genuine. These genuine piece of gold jewellery are stamped with certain form of numbers or letters which indicates its Karat and gold content. There are certain globally recognized letters and numbers which can be helpful to understand while selecting any piece of jewellery.

The genuine and authentic gold jewellery will have a stamp which represents the purity of the gold in it. These symbols (marks), vary from different representations to their formats. To illustrate; 916/917, 22KT, and 22K all represent the same 22 Karat gold. These formats are made available for enhancing basic knowledge about gold to customers.

Then comes three digit numbers to define how pure the gold is as mentioned in the above chart. These are measured in the thousandth and with an easy calculation, one can know the purity percentage, by moving the decimal point in one space, like for an example: 750 is 75.0 % pure gold (or 18Karat). 

There are other marks, symbols which can be included on gold pieces indicating whether a piece has been plated with another metal or not eg. Gold Electroplate is denoted by the symbol “GE” indicating that base of a metal, usually brass and certain other thickness of gold has been deposited on the base, giving it a gold plating.

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