Gold is a yellow precious metal, used in jewellery and decoration and to guarantee the value of currencies. This metal has been a valuable and highly sought after precious metal for coinage, jewellery, and other arts since long before the beginning of recorded history.
A total of 174,100 tonnes of gold have been mined in human history. The world consumption of new gold produced is about 50% in jewellery, 40% in investments, and 10% in industry.
Besides its widespread monetary and symbolic functions, gold has many practical uses in dentistry, electronics, and other fields. Its high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity have led to many uses, including electric wiring, colored-glass production, and gold leafing.
Because of the softness of pure (24k) gold, it is usually alloyed with base metals for use in jewellery, altering its hardness and ductility, melting point, color and other properties. Alloys with lower carat rating, typically 22k, 18k, 14k or 10k, contain higher percentages of copper or other base metals or silver or palladium in the alloy. Copper is the most commonly used base metal, yielding a redder color.
Karat is a unit of purity for gold alloys, rather than weight. The Karat measures the proportion of pure gold mixed with other metal alloy to make up the final metal. We should always remember that Karat and Carat are two different units of measurement, where Karat is a unit of measurement of purity of gold, Carat is a unit to measure the weight of precious stones and gems.
|Purity of Gold / Gold quality - Standards|
|24K Gold quality||too soft for fine jewellery|
|14K/18K Gold quality||ideal for fine jewellery|
|10K Gold quality||affordable for fine jewellery|
|Percent of Purity|
(Parts of gold per 100)
|Gold European System|
(Parts of gold per 1000)
(Parts of gold per 24)
Gold Filled, also called Gold Overlay, refers to a layer of at least 10-Karat gold that has been permanently bonded by heat and pressure to one or more surfaces of the support metal, then rolled or drawn to a prescribed thickness. The Karat gold must be at least 1/10th of the total weight.
Gold Plate means that a layer of plating of 10+ Karat gold has been bonded to a base metal. The Karat gold content may be less than 1/20th, but it must be properly identified by weight in terms of total metal content.
Gold Leaf is just gold plating that's been pounded and applied by hand.
Yellow gold is alloyed with copper, zinc and silver. It is malleable, ductile, and generally non-corrosive, so it has a high melting point and is not susceptible to compression.
White gold is alloyed with copper, zinc and nickel. The percentage of gold naturally varies, according to the amount of other metal used. It is frequently used in diamond jewellery and considered a classic metal choice. White gold is highly reflective and not subject to tarnish.
Rose gold (also known as pink gold) is alloyed with copper, and in some cases silver. The proportions are about one part of copper to three parts of 24-karat gold.
Hallmark is the certificate of the purity of the gold. The process involves evaluation of gold products at Hallmarking & Assaying Centre which are later certified at national and international standards. The Jeweler who intends to get their jewellery hallmarked contacts Bureau of Indian Standards (BIS) for a license, after acquiring the license, the products are sent to Assaying and Certification Centre for certification.
The license is offered by BIS to the jewelers and the manufacturers once they complete the requirements as per IS 1417:1999, which ensures the purity and practice of gold products. The license enables the jeweler to trade the gold with credibility and trust to the customers.
If the product has the Hallmark of BIS’s logo, it signifies major traits like the fineness number, mark of Assaying and Hallmarking Centre (where the jewellery has been marked ) with the year of the mark and the manufacturers mark.
Markings to look for while buying a hallmarked product:
|Fitness||Fineness of Gold|
|958||95.8 % or 23 Karat purity of gold|
|916||91.6% or 22 Karat purity of gold|
|875||87.5% or 21 Karat purity of gold|
|750||75.0% or 18 Karat purity of gold|
|585||58.5% or 14 Karat purity of gold|
|375||37.5% or 09 Karat purity of gold|
The logo of the BIS recognized Assaying and Hallmarking Centre.
A code denoting the date of hallmarking.
Logo of BIS certified jeweler or manufacturer.