Metals Learning Centre
Nothing shines like gold, platinum, and polished tungsten. Learn more about these most precious of metals.
Gold's purity is measured in karats, 24 karat being considered pure gold. Different alloys are used in jewellery for greater strength, durability and colour range.
The "K" or karat of the jewellery will tell you what percentage of gold it contains: 24kt is 100%, 19kt is 79.17%, 18kt is 75%, 14kt is 58.33% and 10kt is 41.66% of gold. When comparing gold jewellery, the higher the number of karats, the greater the value. However the higher the number of karat, or in other words, the higher the purity, the softer and less durable the jewellery item becomes.
When buying gold jewellery, always look for the karat mark. All other factors considered equal, the higher the karat, the more expensive the piece. Nothing less than 10 karat can legally be marked or sold as gold jewellery in North America.
In addition to the karat mark, every piece of gold jewellery should be stamped with a hallmark or trademark of its maker, and sometimes its country of origin. These designations assure you that you are buying genuine karat gold jewellery.
Yellow gold is alloyed with silver and copper. It is the most commonly used type of gold there is. Malleable, ductile, and generally non-corrosive, it has a high melting point and is not susceptible to compression.
White gold is alloyed with a large percentage of silver, or a selection of other white metals such as nickel. The percentage of gold naturally varies, according to the amount of other metal used. White gold is highly reflective and not subject to tarnish. The ancient term for white gold was Electrum. Its use predates that of Palladium and Platinum. Customers frequently question what causes a yellow tint in white gold and if the tint is normal, and whether they should switch to palladium white gold or some other metal for their jewellery.
#1 – Most white gold alloys do have a yellow tint, some more than others based on the percentage of nickel they contain. Nickel is a metal which is mixed or alloyed with gold in order to change its colour from yellow to white – the more nickel, the more white the end result is in a white gold. Today, nickel content in white gold alloys range from 7% to 11%. In previous times, white gold alloys may have contained higher percentage of nickel and would also have been whiter.
So why has it changed, and why everyone is making yellow white gold today? Surprisingly, the answer to these questions can be found on the shelves of supermarket in the dozens of cleaners and disinfectants containing corrosive chemicals like chlorine and bromine. White gold exposed to these chemicals can quickly fail due to stress corrosion, leading to prong failure and stone loss. The higher the nickel percentage is, the greater the risk of stress corrosion.
In recent years, most manufacturers have lowered nickel content in order to improve durability and stone security. In the past, this was unnecessary as there were not as many of these corrosive products available to the consumers. So how can a manufacturer/jeweller achieve a truly white appearance, one free from a yellow tint? In two words, “Rhodium Plating”.
Rose gold is alloyed with a higher percentage of copper, and perhaps silver. The proportions are about one part of copper to three parts of 24-karat gold.
Gold pricing is based on a number of factors, including karat, gram weight, design and craftsmanship. The karat and gram weight tell you how much gold is in a piece, but don't rely on these alone to determine price. Remember, a price based solely on gram weight does not reflect the work that has gone into the piece.
Other important factors to consider are the jewellery's construction and design. A well-made piece will give you years of wear and enjoyment and, if cared for properly, will last a lifetime. Unique design, intricate details, gemstones or a special clasp may add to the price.
Gold is durable, sturdy, dependable, and makes an ideal setting for your precious diamond jewellery. However, to get a lifetime of enjoyment from your jewellery, be sure to keep it clean and safe.
Do not wear jewellery during rough work or when handling harsh chemicals. Store it in a fabric-lined box away from other pieces to preserve it from getting scratched. Finally, check the diamond settings periodically for any damage to the gold prongs or bezels. If you see a loose prong, or if the setting looks out of line, bring it to a professional jewellery for repair as soon as possible.
Platinum, like gold, has a long and distinguished history. Its popularity flourished over the last 200 years. Platinum was held in high esteem during early Egyptian times. Native people in South and Central America worked it as early as 100 B.C.
For centuries, the only large amounts of platinum outside of South America were found in Russian mines. Nowadays, platinum is far more precious than gold. Platinum's primary uses were probably limited by its hardness and its very high melting point. The early forging and casting techniques made it quite a difficult metal to work with.
The demand of platinum is in its appearance. Its white lustre is exclusive. It is also the strongest precious metal used in jewellery, and is almost twice as heavy as 14-karat gold. This weight is one of platinum's strongest selling points.
In recent years platinum’s popularity has grown. It is now an alternate choice for diamond engagement rings because its lustre brings out the brilliance of diamonds along with the traditional white gold.
Despite its growing popularity, platinum remains one of the world's rare metals. It can be found in just a few of regions of the world. The mining and refining processes are both tough and time-consuming. For example, in order to extract a single ounce of platinum, about 10 tons of ore need to be mined. After that, the refining process takes a full five months.
Platinum in jewellery is actually an alloyed group of six heavy metals, including platinum, palladium, rhodium, ruthenium, iridium and osmium. These other metals are so similar to platinum in weight and chemistry that most were not even distinguished from each other until early in the nineteenth century.
Tungsten Carbide is the only rare and exotic metal that can promise permanence in polish and finish that will endure until the end of time.
The original pattern and design in many gold rings will all but disappear after several years. Tungsten Carbide rings will maintain an everlasting beautiful and shiny finish. The heavy weight and the enduring finish of a tungsten carbide ring, speak of commitment, security and an everlasting bond.
Tungsten Rings are the most wear-resistant rings available on the planet.
Tungsten is about 10 times harder than 18K Gold, 5 times harder than tool steel, and 4 times harder than titanium. Tungsten measures between 8 and 9 on the Mohs hardness scale. (Diamonds are a 10 - the highest.) Due to their extreme hardness, Tungsten Rings will hold their shape and shine longer than any ring on the market.
Tungsten rings have been referred to as "Permanently Polished Rings."
Tungsten rings will NOT bend.
In the event of an emergency, a ring can be removed by a medical professional.
Each Tungsten ring is individually hand-crafted using assorted diamond abrasives and polycrystalline diamond tooling. Our Tungsten Carbide rings are cobalt-free. Tungsten with carbon and other elements are ground into a powder and then compressed with high heat and pressure dies to form a ring blank.
The blank is then fired in an oxygen-free furnace at an astounding 6,200 degrees Fahrenheit. This process called sintering creates the hardest metal alloy used in making jewelry. The ring is then cut and shaped using diamond tools with up to 40 total separate steps required for completion. The cutting and shaping of a tungsten ring is similar in many ways to the cutting and polishing of a rough diamond.
Precious metal inlay rings such as gold, silver or platinum are created by grinding a channel in the center of the ring and precisely "wedging" the metal into the channel under extreme pressure. The ring is then skillfully polished with diamond polishing tools and wheels creating a permanent luster and polish not possible with other metals.
A Tungsten Carbide ring will remain polished forever, and is virtually impossible to scratch. It is a unique metal that epitomizes today's technologically advanced man more than any other.
The word Tungsten in Swedish and Danish means "heavy stone." The current name for the element is Wolfram and was founded by Peter Woulfe in 1779 who examined wolframite.
Gold, silver and platinum like Tungsten, is element #74, are heavy elements. It is naturally occurring and is an important element responsible for the development of human civilization. Without tungsten we would not have the filament inside the incandescent light bulb. Tungsten gives the filament the toughness and resilience exceeding any other metal. In 1922 the Germans developed Tungsten Carbide as the material used in making better cutting tool bits for precision milling and cutting of steel.
Tungsten has the highest melting point of all the elements at 6,700 degrees F (3,420 degrees C). Its permanent attributes deem it to be the hardest metal on the planet.
Today tungsten carbide is used throughout the world. Although its primary application is in the mechanical industry, it is quickly gaining popularity as a durable, long lasting, material used in jewelry.