Precious Metals
Gold
Gold was one of the first known metals discovered by man and treasured for its beauty. This asset is in truth due to gold's physical characteristics that means it will not tarnish, rust, or corrode, and though its very strong, it is also the most malleable of all metals.
Pure gold is too soft to withstand the stresses of daily wear, so it is alloyed with a mixture of metals like silver, copper, palladium, and zinc to give it strength and durability. Karatage indicates purity and is noted by a number follwed by the letter "k". Traditionally karatage is expressed in 24ths, meaning 18k gold is an alloy of 18 parts gold and six parts other metal. 24k gold is 100% gold with no alloyed metals. Since 1998 to come in line with Europe the standard marks of purity are expressed as parts per thousand. So 18 karat gold is 750 parts gold to 250 parts of other metals.
24 karat = 99.9 % gold, marked 999
22 Karat = 91.6 % gold, marked 916
18 Karat = 75.0 % gold, marked 750
14 Karat = 58.5 % gold, marked 585
9 Karat = 37.5 % gold, marked 375
White Gold
White gold is produced only by alloying the gold with white metals to form a white metal with a slight yellow colour. Depending upon the clients wishes there are two approaches to the final finishing.
Natural Finish : This finish involves leaving the white gold in its natural metal colour, I find that when producing a piece that combines both white and yellow gold, the slight yellow colour in natural white gold blends and provides a good contrast. This works brilliantly with pieces set with coloured stones.
Rhodium Finish : For those wishing to enhance the whiteness, the white gold can be plated with rhodium, an extremely hard and shiny white metal in the platinum group. Almost all white gold is plated with rhodium which depending on the amount of wear the piece of jewellery is subjected to, over time this rhodium may wear off to reveal the original metal colour. The finish can be easily restored through having the rhodium re-applied .
Rose Gold ( Also known as Red Gold )
Rose gold is produced through alloying the gold with pure copper, with a touch of silver to form a reddish metal.
Platinum
Platinum is around thirty times rarer than gold, with its stunning white finish platinum's most appealing characteristic may be its durability. When other metals are scratched or polished, tiny bits of the metal may be lost. A scratch in platinum may leave a mark on the metal, but this metal is so strong that it will not readily chip or splinter. Even very slim platinum designs and settings will permanently retain their shape. It is also hypoallergenic, will not tarnish or discolour and for these reasons, platinum makes an excellent overall choice for pieces of jewellery.
Platinum is alloyed with a mixture of metals like iridium, palladium, ruthenium and other alloys to give it different characteristics. To indicate the purity of platinum it is graded by the percentage of platinum present to other metals. The purity is expressed in parts per thousand, meaning platinum marked 950 is an alloy of 950 parts platinum and fifty parts other metal. 1000 parts of platinum has no alloyed metals. The following standards apply for platinum in the UK.
999 = 99.9 % platinum, marked 999
950 = 95.0 % platinum, marked 950
900 = 90.0 % platinum, marked 900
850 = 85.0 % platinum, marked 850
For all platinum jewellery I produce I use the 950 standard of fineness, as it provides the best blend of strength and durability while still being able to be worked or cast with relative ease. For pieces such as my handmade key rings, should someone wish for such a thing I can craft a piece making use of the 999 standard of fineness.
Palladium
Palladium has become the latest fashion for fine quality jewellery and offers a vastly superior alternative to white gold. As a metal it can be best thought of as a sister metal to platinum. Its key characteristics include:
Palladium is naturally white and will not tarnish. Like platinum, palladium does not require rhodium plating and will maintain its bright white colour indefinitely.
As a metal palladium is 30 times more rare than gold.
Palladium is lighter than platinum. Palladium's density is roughly half that of platinum, making it ideal for earrings, necklaces, and pendants that might otherwise be too heavy in platinum.
Palladium rarely causes allergic reactions, allowing many people who are unable to wear white gold alloys due to the wide use of nickel as an alloying element will find palladium to be a great alternative.