What is 24k Gold?
Introduction to Gold
Gold, known also by scientific types by its periodic table element of Au, is a highly prized, rare metal, revered and valued worldwide. It is used in a variety of ways from crafting into jewellery and even beauty preparations for the luxury cosmetic industry, through to scientific and engineering uses, where its conductive properties are useful for industry and technology development. Many of us wear it and adorn ourselves with gold jewellery. Some of us will have gold fillings and others will find it included in luxury skin preparations, on the nibs of ballpoint pens and in a variety of surprising everyday uses.
Gold's History
Gold has long been used as a currency, a symbol and token of affection with its value long recognised. Its earliest history dates back to the earliest civilisations in the Middle East and throughout history, it has led to untold riches for the few. It has also kick-started turf wars and changes in society. The gold rushes in America, Australia and Latin America were great examples of colonies forming around the lure of gold. Since then, we've been enraptured, prizing gold alongside the precious jewels it so often encases. Whether it's an engraved gold necklace from a loved one, an engagement ring, or an heirloom piece for the home, gold continues to captivate and entrance us. It also holds its value well, something of real interest in a turbulent economic market.
How is it Recovered?
The two most common methods of recovering gold are via panning or mining. Mining for gold dates back to 3500 BC, when local labourers were used to painstakingly remove gold particles from the earth using labour intensive, often dangerous mining expeditions. Panning was a technique made famous by the modern historical 'Gold Rushes', when panners would sift sand and gravel in shallow pans to search for small gold deposits, lifted from streambeds. Modern methods include metal detectors and advanced industrial mining, where lode deposits are extracted by blasting or drilling and placer deposits are extracted via panning or hydraulic mining. Once the gold has been recovered and separated, it can then move to the next stage of the process, which is refining.
What is Gold Refining?
After the gold is separated from its ore, it can be refined and will follow a four-stage process - flotation, amalgamation, cyanidation and carbon in pup. These processes will depend on the initial gold ore grinding and will involve combining it with solutions and chemicals in a bid to extract the gold. Because pure gold is ductile and malleable, it is often alloyed with other stronger metals such as copper, silver, nickel or platinum for use in jewellery or coins. These alloys are chosen for their specific chemical properties, their ability to strengthen the gold and even for visual interest, to make coloured gold.
Gold Manufacturing
The famous gold bars we know from images of untold riches are actually produced from bulk deposits of melted down gold, which are produced in large moulds (crucibles) in induction furnaces. The melted gold is poured into a transfer crucible, then a sized mould, made from cast-iron. Once poured, they are poured into water tanks to cool and then cleaned, weighed and marked with a stamp and weight (detailing the serial number, manufacturing batch, refiner and details of its purity). From this stage, the gold is ready to be distributed for onward manufacture and use.
How is it Measured?
Of course, there is a vast difference between the gold found in an inexpensive pair of earrings and the type found in high-end jewellery or used in artisan metallurgy. Gold is measured using a standard carat system. The rating, which goes up to a pure gold maximum of 24 carats, represents the proportion of solid gold elements found in a single item. For example, an 18 carat gold item is made up of eighteen parts gold, six parts other materials (such as metals). 24 carat gold is the most rare type of gold and made up entirely of 100% gold. Hallmark systems are also used to grade gold, with the purest rating at 1000, or commonly 999, due to the incredible difficulty of finding truly pure gold without any type of impurity in it (this protects the manufacturer too from potential legal challenges). Gold coins will generally be produced as 24 carats and be rated as 999 parts to 1000.
What are Gold's Uses?
We firstly think of jewellery when we think of gold, but particularly when it comes to the purest 24 carat gold, scientific and industrial uses are commonplace. For example, coins can be made from gold and gold ore may be extracted for commercial use, using a process known as amalgamation. In this process, gold ore mixes with mercury to bond it and the mercury is then removed by another technical process called retorting. Gold is also dissolvable, using aqua regia, a mix of acids and potassium cyanide.
What about Gold's Use in Jewellery?
24 carat gold is the most prized and expensive. However, it is soft and can be damaged more easily than lower grades. For this reason it tends to be mixed with stronger alloys to make it more durable and easy to work with. The most common method of making jewellery from gold is the casting method of 'lost wax'. The object is sculpted initially in wax, which is then cased into plaster to dry and then baked in a kiln. During baking, the wax melts and a hollow sculpted shape is left inside, producing a casting shape for the gold to be moulded into. Different colour golds can be created, such as white gold, yellow gold and even rose gold, according to preferences and refining techniques used.
24 Carat Gold Jewellery
Jewellery made from 24 carat gold will be prized for its purity but it generally isn't strong enough to withstand use, so will tend to be combined with an alloy and made into 18 carat gold, often combined with precious stones. It will be the most expensive form of gold, but the most treasured and maintained and if cared for properly, it can become a lasting heirloom and item to treasure. Often, gold jewellery items are designed according to bespoke requests and designers will work with the customer to create something that matches their personal tastes, individuality and vision for the piece, whether that's a ring, necklace or larger sculptural or decorative piece.