Metals Used in Jewellery – Which is Best for You?

Pure gold or fine gold is 24 Karat.  What does 14K mean?   What is gold filled, gold-plated and rolled gold?  Why is sterling silver called 925?  What metals are part of the platinum group?

Gold and Silver Bars

Gold & Silver Flickr Photo by digitalmoneyworld

What Metals Are Used in Fine Jewelry?

Gold, silver and platinum are commonly used in fine jewellery.  Many more metals are used in jewellery today as the consumer would like to buy more jewellery, but not spend a lot of money.

Silver Quality Marks and Other Silvers (That Do Not Contain Silver)

925 silver means that 925 parts out of 1000 are silver (92.5%) and the rest are some other metals.  The quality marks or a decimal figure may be used on articles containing a minimum of 92.5% pure silver.  The most popular silver is sterling silver which is an alloy of 92.5% silver and 7.5% copper. Sometimes copper is replaced by zinc or platinum to reinforce some of its properties.  Britannia silver is an alloy of silver containing 95.84% silver, with 4% of copper.

Some metals may be called ‘silver’ when, in fact, they are not (except in colouration). For example, nickel silver (also know as German silver) is an alloy consisting of about 60% copper, about 20% nickel, about 20% zinc, and sometimes about 5% tin (in which case the alloy is called alpaca).  There is no silver at all in German silver, nickel silver or alpaca silver.

Cartagena Gold Museum Colombia

Cartagena Gold Museum Flickr Photo Roubicek

What do The Gold Quality Marks Mean?

For gold, karat grade is used to express the proportion of gold in an alloy or the quality of a gold alloy. Fine gold (pure) is 24 karat. The proportions in other karats are listed in the table below.

All jewelry is required by law to be stamped so consumers will know the quality of gold used.   In Canada, the use of a quality mark is not compulsory, but the Precious Metals Marking Act and  Regulations provide a number of permissible quality marks. If businesses choose to apply quality marks, they must do so as prescribed by the Act and the Regulations, including a trade-mark that has been applied for, or registered, is an example of one such requirement. Jewellery made in North America is typically marked with the karat grade (10K, 14K, etc.), and jewellery made in Italy is typically marked with the “fineness” such as (417, 583, etc.).  So if your jewellery does not have a karat grade stamped on it, check for a 3-digit fineness number.

Karats Parts Gold to Alloy Percentage Fineness
10K 10/24 41.67 417
14K 14/24 58.33 583
18K 18/24 75.00 750
22K 122/24 91.66 917

White and Coloured Golds

Coloured golds are produced by alloying other metals that give their colour characteristics to the gold.  White gold is made by alloying gold with white metals, such a palladium, nickel and manganese.  Rose gold, also known as pink gold or red gold, is a gold and copper alloy.

Gold Plating, Gold Filled and Rolled Gold

Gold plating is a method of depositing a thin layer of gold onto the surface of another metal by an electrolytic process.  Gold plating of silver is used in the manufacture of jewellery. Silver atoms diffuse into the gold layer, causing slow gradual fading of its colour and eventually causing tarnishing of the surface. This process may take months and even years, depending on the thickness of the gold layer.  The layer must be a minimum of 10K and be at least .175 microns thick.   This is the standard that is used for most base metal jewellery & findings.  (One micron is one millionth of a meter, a human hair is roughly 100 microns)

Gold filled means that the article is a base metal with a layer of gold fused to its surface.  This layer is at least 10K fine.  The industry standard is to clad the base metal with 10% (by weight) 12K.  Since 12K is half pure gold then the final product would be 1/20 or 5% pure.  Gold filled items are commonly marked “1/20 G.F.”, “1/20 12 K G.F.” or “1/20 12K gold filled”.  It has a much thicker layer of surface gold than gold plating.

Rolled gold is a layer that is only half as this (1/40th).  The US Federal Trade Commission allows the use of “Rolled Gold Plate” or “R.G.P”. on items with lower thicknesses of gold than are required for “gold-filled.” A 12 kt gold layer that is 1/60 the weight of the total item is designated as 1/60 12kt RGP.

Platinum, Palladium and the rest of the Platinum Group

Platinum is a tough, dense, white metal used primarily for diamond settings.  It is resistant to corrosion and wear.

Metal Description Hardness
Platinum In jewelry, usually as a 90–95% alloy, due to its inertness and shine 4-4.5
Palladium Used in alloys with gold or platinum in expensive jewellery 4-4.5
Rhodium Used as a plating over white gold to add toughness and over sterling to add toughness and resists tarnish 5
Iridium Added to platinum to add even further toughness 6.5
Osmium Plated onto manufactured goods, adds resistance to contact surfaces 7
Ruthenium Added to platinum and palladium to add toughness, it has a dark appearance from light-grey through grey-black 6.5

Which Metal Looks Best on You?

Most people look best in either white metals or yellow metals depending on their skin tone.

Determine Your Skin Tone.  Locate an area on your body where veins are visible, usually the wrist serves as a good reference point.  Based on the colour of your veins, your skin tone may fall into one of two categories, cool or warm:

  • Cool skin tones are identifiable by bluish coloured veins.  People with cooler skin tones may notice pinkish or rosy-red undertones when looking in the mirror.  Eye colour can range from light blue to dark brown and anywhere in between.  Most people have cool skin, including people with dark skin and tan skin.
  • Warm skin tones are identifiable by greenish coloured veins.  People with warmer skin tones may notice yellow or golden-apricot undertones when looking in the mirror.  Eye colour can, again, be any colour.  People whose natural hair colour is red, orange, or strawberry blonde almost always have a warm skin tone.  Sometimes hair may be more brown, but it will have a reddish tint.  People with darker skin are not usually warm-skinned.
    • Cool skin tones look best with metals such as silver, platinum, and white gold.
    • Warm skin tones look best with metals such as gold, pewter, brass, and copper.

What ever your skin tone, also be sure to consider price, design, metal quality and durability. You want to enjoy your jewellery for a very long time!

Your Input

(Join our poll or Scroll Down To The Bottom and leave a comment) – Emerald is winning the poll!

Gold Bars

Gold Bars Flickr Photo digitalmoneyworld

I have introduced different gemstones alphabetically.  I started with “A” (Ammolite) and it has taken me to Malachite!  Leave a comment and let me know if you have a favourite gemstone that starts with the letter “O”.  Take the poll!  Can you name a reference to a gemstone in a song, movie or book?

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About Jen McKercher

Jennifer McKercher teaches gemmology at the Canadian Gemmological Association. A passion for gemstones drives Jen to learn as much as she can about the wonders of gemstones and how they enhance our lives.

Posted on November 24, 2011, in Jewellery and tagged , , , , , . Bookmark the permalink. Leave a comment.

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