A Guide to Gold

Gold has always been revered for its rarity and beauty. All through history, Gold has always been a symbol of wealth which signified luxury in all its forms. Be it currency, crowns, armours or jewellery etc Gold has been used for making all of the above. Of the oldest civilizations, first recorded use of gold was seen by the Indus valley, Mesopotamia and Egyptian Civilizations in forms of coins, crowns and jewellery. Let’s see a little more in detail about Gold.

Gold - Origin and Extraction

Gold is found in the form of ores in rock formed in the crust of earth. Gold occurs as very small to microscopic particles embedded in rock, often together with quartz or minerals in the form of free flakes, grains or larger nuggets.

The production of gold is a complex process consisting of 3 main phases:

• ● Mining process of gold ore
• ● Refining process of ore into industrial gold
• ● Separation process into fine gold.

In the last step of gold processing, refineries analyse the gold obtained and separate it from other minerals and elements. The result is fine gold with up to 99.99 % gold content - the outcome of gold production.

This is the purest form of gold which is then shaped in bars which is what is then used in jewellery making.

Gold 101

Gold as a metal has important features which makes it the most preferred metal for jewellery making.

• ● Gold is a noble metal which means it resists oxidation and corrosion in moist air. It possesses varying degrees of resistance to acids.
• ● Gold is the most malleable, ductile and soft of all known metals. It can be easily beaten into a sheet of gold or pulled into wires and can be crafted into any shape which is perfectly suitable for jewellery making.
• ● Gold possesses lustre and sheen because of which it highly reflects light. It is because of this; Gold jewellery appeals to the eye the most.
• ● Gold is innate with rich golden, yellow colour in its purest form. Over the years, addition of different metals introduces a different range of Gold colours which have gained popularity with time.
• ● Gold as a metal is hypoallergenic which means it does not react to skin. This is one of the reasons why gold as a metal is used majorly in jewellery making.

Gold Purity

Whenever we purchase gold jewellery, gold coins or Gold bars etc, we often hear the term “KARAT” or “KARATAGE.” For measuring the purity of gold, “Karat” is a worldwide accepted unit of measure.

A simple rule when understanding Purity of Gold is - “the higher the numerical value of Karat, the higher is the purity of Gold.

When we hear anything made of 24 Karat Gold, it means it is the highest form of gold purity. But this form of gold is so soft that it cannot be given any desired shape. In order to do so, some percentage of other metal. This varies with the ratio of parts.

“24 karat” or “24kt” means it is made of 24 parts of Gold, it has no impurity.

As the purity decreases, the ratio of Gold part varies. Ratio of pure gold metal to other added metal is calculated on the whole 24 parts of Gold.

22 kt means 22 parts out of 24 is pure gold and 2 parts is other added metal.

This rule is followed in decreasing order when calculating different karats.

When it comes to Gold jewellery following Karatage are used by different brands worldwide.

To convert Karats into the percentage, you need to divide the karat number by 24 and multiply the result by 100.

Types of Gold

Gold jewellery has been made in its original rich yellow colour for centuries. But in the past few years, other hues and colours in jewellery have gained popularity.

Yellow Gold

Yellow gold is innate with a rich golden color. When used for jewellery, it is often mixed with sterling silver, copper, and zinc to give it added strength and durability in any karat.

White Gold

White gold blend is created when yellow gold is mixed with nickel or palladium and zinc. Visually similar to Platinum, white gold gets its bright, silvery-white finish from Rhodium plating. White Rhodium plating is a process of giving shiny white metal finish but unlike yellow Gold, it wears off with time.

Rose Gold

Rose gold blend is created when yellow gold is mixed with copper and silver. The depth of color in the rose gold depends on the ratio of yellow gold to copper. Less yellow gold, and a higher copper content will result in a more reddish rose color.

Rose gold is a subtle and well accepted as a color of gold that translates into romantic and elegant fine jewellery and engagement rings. And it is because of this richness of the color, it has gained tremendous popularity in recent years.

Following table shows the combinations of different Golds in different karatage.

The metal compositions mentioned above are standards used by the jewellery industry but these are not the only combinations to be used. Many brands use further different combinations.

Gold Plated Jewellery

We have often heard the term “Gold Plated jewellery” on any of our visits to Jewellery house. What is Gold plated Jewellery, is it authentic gold jewellery or different, why is it done etc are some of the commonly asked queries that we often get confused about. So, let’s understand it.

What is Gold Plating?

Gold plating is a process of depositing a thin layer of gold onto the surface of another metal, most by chemical or electrochemical plating. Gold Plating is used in many other fields apart from Jewellery.

For Gold Plated jewellery, the jewellery piece is immersed in an electrolyte solution and electrical current is applied so that gold metal gets coated on the piece of jewellery, thereby creating a thin layer of gold on the jewellery. How long the component is left in its bath typically determines the thickness of the plating.

Gold plating can be added to almost any metal, including brass, copper or nickel. Silver items can also be gold-plated. Gold plating of silver is used in the manufacture of jewellery. The thickness of gold plating on jewellery is noted in microns (or micrometers). The microns of thickness determine how long the gold plating lasts with usage.

Gold Plating or Gold electroplating is done by jewellers and is a fairly common service.

Why is Gold Plating done?

There are quite a few reasons why Gold plating is done.

• ● As mentioned above, Gold plating is done for silver or lesser metals like copper. This gives an appearance of silver and gold but they are affordable when being purchased. Many jewellers mention specifically that their jewellery is Gold plated. A huge niche caters to this type of jewellery.
• ● Metals like Silver or copper have tendencies to react with climate. Gold plating these metals helps to slow down their oxidation rate, so they do not tarnish. But no matter, after some time, they lose their tarnish.
• ● For many customers who have sensitive skin, Gold plated jewellery is a viable option.

Dos and Don’t when wearing Gold Plated Jewellery

Whenever handling any type of jewellery, a certain measure of care needs to be taken.

Some of measures are mentioned below:

• ● Avoid bringing your Gold-plated jewellery in contact when using water or heat.
• ● Avoid wearing them when using any chemicals, lotions, body creams or hair spray as they tend to react.
• ● Always take off your jewellery before a workout, as sweat can cause jewellery to tarnish.
• ● The harder an object is rubbed, the faster its plating will wear away. So, when cleaning, do not wipe your jewellery hard with cloth or tissue. Use a lint free cloth and wipe gently.
• ● When storing them, use anti tarnish strips and a good packed jewellery box.
• ● At any time, you need professional cleaning or gold plating, request for the service with your jeweller.

Real Gold Jewellery vs Gold Plated jewellery

How can you determine if a piece is real gold or other precious metal? Or if it’s plated?

This can be with XRF (X-ray fluorescence) technology. Non-destructive analytical technique, it is used to determine the elemental composition of materials. There are portable XRF analyzers that can perform an accurate non-destructive analysis of the precious metals. Gold spectrometers quickly provide the exact karat weights, percentages of all elements within a jewellery item - easily identifying non-standard, under-karated, and even advanced counterfeit gold. They can quickly distinguish between gold plating and solid gold, as well as determine the presence and concentration of other trace alloying elements.