Gold can be alloyed with other metals and comes in many colours.
||ALLOYS ADDED TO GOLD
|| silver copper
||zinc, copper, tin and manganese
||copper and silver
||High proportion of silver or cadmium
A Cold Enamelled Charm
Gold, Silver, Platinum, Palladium and Titanium are precious metals, meaning they are rare metallic chemical elements of high economic value, shiny, hard, strong with high melting points. They form alloys (mixtures) with other metals and this makes them ideal for jewellery.
Gold is a highly sought-after rare metallic element. For many centuries gold has been used for money, jewellery and ornamentation symbolising wealth and prosperity. Like other precious metals, gold is measured by troy weight and by grams. When it is alloyed with other metals the term carat (or karat in the USA) is used to indicate the amount of gold present. Pure gold is twenty-four twenty-fourths (24/24ths) gold, and is called 24-carat gold. Gold that is 18-caret gold is eighteen twenty-fourths (18/24ths) gold and six twenty-fourths (6/24ths) other metals. Only 24-carat gold is 100% pure gold.
Its chemical symbol, Au, is short for the Latin word for gold, "Aurum", which means "Glowing Dawn". Is a very soft metal when it is pure (24ct). It is often alloyed with other metals to make it harder though this lessens the value. Pure gold has an attractive bright yellow colour however when alloyed with other metals it can come in other colours. It is non reactive to air and water.
Silver was once thought more precious than gold. It is a very soft metal and is often mixed with an alloy like copper. The term "Sterling Silver" probably originated in eastern Germany where they minted coins of .925 percent silver. When Britain sold cattle and grain to this area they were paid in "Easterling coins". These coins were found be be resilient and durable so King Henry II decided to adopt the standard .925 coins for Britain's own currency and set up a royal mint to produce silver coins. The term easterling silver was eventually shortened to sterling silver. To be sterling silver, the metal is made up of 92.5 percent silver and 7.5 percent copper.
Silver has been used to make jewellery for many thousands of years. These days most silver is produced as a by-product of copper, gold, lead, and zinc mining. Silver tarnishes after exposure to air (a thin layer
of silver oxide forms on the surface). The best way to deal with this is use silver dip or wipe with
an impregnated cloth.
We can also repolish any item to return it to its original condition.
Platinum (PT) - Platinum is more precious than gold, it is a very strong dense
metal that never corrodes. In its pure form it is harder than gold and silver so for jewellery it is alloyed with 5% of other metals, usually Iridium (another even rarer metal in the platinum family) to make it more workable. Naturally-occurring platinum has been known for a long time. The metal was used by pre-Columbian Native Americans, the first European reference to platinum appears in 1557 in the writings Julius Caesar Scaliger as a description of a mysterious metal found in Central American mines. It is a rare greyish white metal, ten tons of ore have to be mind to produce a single ounce of platinum. The word platinum comes from the Spanish word platina, meaning "little silver."
Platinum exists in relatively higher abundance on the Moon.
Palladium (Pd) - Palladium was discovered in 1803 and named after the asteroid Pallas. It is an element belonging to the platinum group of metals, Palladium is steel-white in colour, except in powder form, when it appears black. Palladium resists tarnishing in air and if annealed (a form of heat treatment) it is soft and ductile. Most palladium is used for catalytic converters in the automobile industry, it is also used in dentistry and now in jewellery
due to its naturally white properties. It will develop a hazy patina over time and will discolour at soldering temperatures. Palladium becomes brittle with repeated heating and cooling.
Palladium is one of three most used metals which can be alloyed with gold to produce white gold. Palladium-gold is a much more expensive alloy than nickel-gold but is hypoallergenic and holds its white colour better.
Titanium - Titanium is not a rare element, its the 9th most common element, accounting for 0.6 % of the earth's crust. The name titanium comes from the Titans of Greek mythology, known for their superior strength.
It is a silvery white non ferrous metal with the highest strength to weight ratio of any known element, 85% of the structural components in the Space Shuttle are made of titanium. Titanium does not react to salt, water, sunlight or any body chemistry, has a diminished potential for causing an allergic reaction and is corrosion resistant. Titanium has become more popular for jewellery in recent years. Titanium cannot be repaired or soldered.
Assay - An assay is a test of the purity of an alloy. A tiny area of metal is scraped from the piece of jewellery and the
percentage of gold or silver is determined, it is then given the appropriate Hallmark.
Types of Finishes - We are able to offer the following finishes Sand Blasted, Satin,
Rhodium Plating, gilding, Hard Gold Plating, Silver Plating and Diamond Cutting.
Plating - Plating is a process that coats a metal usually with a bright coloured plating changing the original appearance. It makes standard yellow gold chains change to a gleaming yellow or white metal to a mirror like finish with rhodium.
All white gold contains a trace element of yellow gold and to compensate for this manufacturers plate the metal with rhodium (which is part of the platinum family of metals)which gives it a very strong white colour. This colour is more in keeping with the public perception that white gold is actually white rather than an alloy of yellow gold. Pieces of jewellery are put into chemical baths that have the various plating solutions in.
An electronic current is passed through the plating solution which causes the plating to bond onto the metal.
If the item has two different colours then we first have to mask off the metal that we do not wish to be plated leaving exposed the area that needs plating.
N.B. Gilding and Rhodium plating are the two most common types of finishing we carry out, these are only a very thin surface covering and will usually only last a limited period of time depending on wear and tear. Customers should be advised to take care to prolong the life of the plating.
Rolled Gold - Rolled gold is a very thin sheet of gold that is laminated to a lesser metal (usually brass or copper). The two layers of metal are heated under pressure to fuse them together. The sheet is then rolled into a very thin sheet and then used to make jewellery or other objects e.g. pens. The gold will wear off over time, we can guild certain items. gilding is a very thin surface covering and will usually only last a limited period of time depending on wear and tear. Rolled gold pieces are marked rolled gold plate, R.G.P., or plaqué d'or laminé.
Enamelling- There are two types of enamelling - Hard and Cold.
Hard enamelling is the fusion of a special powdered glass to metals. The glass powder can be applied using different techniques, but all methods use heat to melt the powder. We don't undertake hard enamelling on the premises, as this requires specialist equipment it has to be sent away.
Most jewellery now is cold enamel which doesn't have the durability of hard enamel.
Cold enamelling refers to enamel paint which we can do on the premises.
Laser soldering requires less heat to repair jewellery. This is beneficial in cases where a jewellery items contains more fragile gemstones, previously these stones would have to be removed. Silver jewellery can be repaired much more easily with this process. We can also repair metals that are non-precious, such as those used in costume jewellery or fashion accessories.
Faulty Gold - Sometimes during the repair of an item
the gold appears to shatter or snap this is due to the fact
that the metal is faulty, if this occurs the item is unrepairable.
The fault occurs during the manufacturing process of the item
due to such factors as overheating during the casting process
or impurities in the metals.
Metal Allergies - If wearing certain jewellery causes localized areas of skin to become itchy, red and/or swollen this can indicate an allergic reaction to the metals in jewellery. Nickel is the most common culprit; if a 9ct gold piercing, bracelet, necklace or ring is causing a reaction, it’s the nickel in the gold—not the gold itself—causing the problem. Women are more commonly affected by a nickel allergy than men. People rarely have a reaction to pure gold (24k), platinum or titanium. There is a risk of allergic reactions with sterling silver too. European Directive 94/27/EC was made UK Law in 2000 and specifies the upper limit for nickel release in articles which have direct and prolonged contact with the skin - such as Jewellery, fashion accessories, and metal adornments for apparel. It also specifies the upper limit for nickel content in specified articles.
The term hypoallergenic was made up in the 1950's as part of an advertising campaign and has since been adopted to indicate that the metal used has a diminished potential for causing an allergic reaction.
Tarnishing - Some, not all, metals tarnish. The discoloration occurs when the metal is able to react with or be attacked by something that can make a chemical compound with the underlying metal. (A chemical compound is a substance consisting of two or more different elements chemically bonded together). Silver can react with oxygen or sulphur compounds to form a brownish-to-black tarnish film. This is due to the formation of oxides (An oxide is a chemical compound containing at least one oxygen atom as well as at least one other element) and/or sulphides (a compound of sulphur and an element that has a more positive electric charge) on the metal surface. Because of the small particle size, the oxide/sulphide particles on the surface appear black, so the metal loses its lustre. Pure gold is resistant to such reactions however lower carat golds are all alloys of gold with other metals and as such can tarnish. Wherever it occurs, tarnish almost always looks very different from the original polished metal. Tarnish is removed either by employing another chemical reaction to dissolve the tarnished surface or by using a mild abrasive to actually polish away the discoloured compound on the metal to expose the underlying metal again. Ordinarily, such cleaning processes remove very little of the original metal.