Colour Of Metal

The Colour Of Metal


The Colour Of Precious Metals

 The first thing to mention is that it is so difficult to convey the true colour of a metal by photograph, and through so many different monitors, TV’s and mobile devices. The best way is to see them in person to compare. The next thing to mention, is that there are hundreds of recipes for making up precious metal alloys. So there isn’t only one colour for white gold, red gold and yellow gold. All I can talk about here, is the specific alloys that I use. In addition, not all metals that you see are natural, that is to say, they might have been plated to enhance their colour.

It is best to see these metals in person, to be able to compare their hues in natural light.

Colour of precious metals

High Polish and Brushed Satin Finish

Every metal can be finished with either a high polish or a brushed satin finish.

The high polish surface is simply devoid of any scratches. You can see your reflection in it and therefore resembles a mirror surface.

The brushed satin finish is the opposite. It has a series of microscopically small scratches. These brushed scratches scatter the light and you therefore do not get a reflection.

There is not such thing as the best finish, just personal preference of which one you prefer.

sterling silver handwriting

Sterling Silver

Sterling Silver (Above) is an alloy where the elements silver and copper are added together, as silver on its own is too soft. The copper makes the resulting mix a little stronger.

925 parts of silver are mixed with 75 parts copper.

This is the whitest of all the white metals. It is also the softest of all the white metals.

It will readily tarnish (go grey and/or black). This can happen naturally or can happen quickly if certain chemicals are involved. (Swimming pools, jacuzzi’s or some beauty products can achieve this) For more info on 925 Sterling Silver, visit this page

9k gold red white yellow

9k Gold -White

Shown here in the middle of the picture above.

Not all white golds are equally white. There are variations of white gold from as “white as is chemically possible” to whiteish (that is to say it has a distinct cream colour but isn’t actually yellow gold. This is somewhat confusing.

You will find that the cheaper whit egold alloys to make are actually a cream colour. These are then typically rhodium plated. The rhodium is a covering that hides the cream colour temporarily and makes the item very white. This is to hide the fact that a cheaper alloy was used and it a widespread practice on the high street where profit is king and not the consumer !!!!!

I use a high white gold alloy. As white as chemically possible, yet it has a slight cream tint. It doesn’t require rhodium plating but will never be as white as sterling silver.

9k golds yellow white red

9k Gold -Yellow

A yellow gold alloy (Above on left)  is made with a mixture of copper and other white metals such as silver and zinc.

9k is required to have 375 parts gold and 625 parts other alloying metals. Depending what other metals are added, you end up with either red gold, yellow gold or white gold. Therefore there are litterally thousands of recipes for making 9k golds. So you may well find a subtle difference between 9k golds, depending which bullion house made them.

9k gold red white

9k Gold -Red (also called pink or rose)

9k Red Gold (Above on left) There are only two non-white metals in the periodic table. Gold and copper. All other metals are white or whiteish or grey.

So to make yellow gold into a red gold (also called rose or pink) you need to add a higher percentage of copper.

Less copper and more white metal in the mix, will produce a yellow gold.

Above is a comparison of the white metals.

None have been rhodium plated, so will be the same colour today, tomorrow and 20 years from now.

It is still hard to capture the true tonal difference of the different white metals in a photo, let alone how that picture displays on umpteen different phones, tablets and monitors.

Sterling silver is the whitest. 9k white gold has a soft warm light cream tone. Palladium, 18k white gold and platinum are difficult to tell apart. They all have a colder steely grey tone.

palladium fingerprint ring

Palladium

(Above) A fairly new metal to the consumer but not new to the jewellery industry. First discovered in its own right as an element back in 1900, but it then took 10 years to convince the world that it was an element and not a naturally ocurring alloy of platinum.

It sits above platinum on the periodic table and inbetween silver and rhodium.

The 1974 UK hallmarking act stated that only precious metals of silver, gold or platinum had to be hallmarked. Palladium was increasingly used as a white metal in the early 2000’s and saw the Assay offices losing income as more and more items were being made form palladium.

So Jan 1st 2010, they changed the law, so palladium is now treated as silver, gold and platinum and requires hallmarking.

It is slightly heavier than 9k and has a cold soft grey tone.

It is typically made in an alloy of 950 parts palladium and 50 parts other metal.

18k white gold

18k Gold - White

(Above) 18k Gold has to have 750 parts gold and 250 parts other alloying metal.

Like 9k golds, depending what metals you add to the mix, you get either white gold, yellow gold or red gold.

An 18k gold made with silver, zinc and other cheap white metals will actually be creamy in colour. It will require rhodium plating to make it whiter. This cheaper alloy is often used by high street chains.

A whiter alloy can be achieved using palladium. Known as a high palladium white alloy. It borrows the cold steely grey tone of the palladium. It is not as white as sterling silver, but does not require rhodium plating and will not turn yellow over time.

18k yellow gold

18k Gold - Yellow

(Above) All 18k gold alloys have to have a minimum of 750 parts gold. 250 parts other metals.

Ths is the standard yellow gold alloy of the UK. Slightly more yellow than the 9k version as it has twice the gold content.

18k red gold

18k Gold - Red ( also called rose or pink)

(Above) This alloy of gold simply has a higher percentage of copper ‘versus’ the yellow gold alloy

A lovely colour but not as fashionable as it use to be, but certainly on its way back.

platinum

Platinum

(Above) The rarest of the bunch.

You have to remove 10 times the volume of earth as you do for gold. It is not only rarer but more costly to mine.

It is harder to work and take s a jeweller longer and requires specialist tools to melt, solder and work with it.

It is inert and will never tarnish. Typically a platinum alloy is 950 parts platinum and 50 parts other white metals.

It is the densest metal and therefore the heaviest. Volume for volume, it is twice as heavy as sterling silver.

It has a steely grey colour, quite hard to tell the difference between this and palladium.

It is the best metal to make rings or settings from, as it does not wear away. It has a clay-like cloying quality which means it hangs on to itself. In comparison to the other precious metals which will happily be worn away and leave trace amounts of themselves on other objects.

hallmark

UK Hallmark

I am registered at the London Assay Office.

UK law requires an item made in precious metal to be hallmarked. Specifically if it is heavier than 7.78g in silver, 1g in gold and palladium and 0.5g in platinum.

It is over 700 years old and means that a UK piece of jewellery has been independantly tested and marked. It is your peace of mind that is is genuine. Other countries rely on the maker to mark their own jewellery. That is obviously open to some abuse. Be cautious when buying jewellery abroad.

A hallmark will typically have several marks. The maker, the metal, the place of hallmarking, the year.

More details can be found here  The London Assay Office

kent jewellery workshop

Rhodium Plating.

Some metals are rhodium plated.

Rhodium is a white metal that can be electroplated onto anothe rmetal. Typically 30 microns thick, so in the great scheme of things, quite thin.

It will wear off. Typically it will last 6-12 months before it is noticeable. The high street chain stores seem to love to plate everything. They won’t tell you in advance.

It can obviously get expensive to re-plate an item yearly. So I do suggest buying a metal whose naturaly colour you prefer. It will then be maintenance free.

I would never recommend plating a yellow or red gold item, as this will look very shabby very quickly when the stronger colour shines through after some wear and tear.

I can plate and re-plate items for you. The cost is £30 for an average sized ring.