What is Gold-Filled Jewelry? How Much Gold Is Really In It?

There are three metals that are known as "precious" metals:  Gold, Silver, and Platinum.  Other metals used in jewelry are known as "base metals" and these include brass, bronze, copper, nickel, and so forth.  Most costume jewelry is made out of base metals.  "Fine" jewelry is made from precious metals.  Pure gold (24k) is too soft to hold gemstones securely over time, so it's alloyed (mixed) with other metals.  This is how we get 18k gold, 14k gold, 12k and 10k gold, etc. and also how we get various colors of gold---rose gold, white gold, green gold.   Pure silver is also alloyed with other metals (primarily copper) resulting in Sterling Silver (92.5% silver).

What Is Gold Filled?
In the jewelry industry, there are different terms for Gold Filled:  it can also be referred to as "rolled gold", "metal cladding" or "gold overlay".  There are standards for gold filled, and basically a thin sheet of karat gold (10k, 12k, 14k) is fused to a thicker sheet of base metal (brass, bronze, nickel or even steel) by heating the two sheets of metal to 900 degrees C, then rolling the metals together under high pressure (about 2500 psi).  The metals are now bonded.  This becomes a rigid sheet of welded metal that is karat gold on the outside----the part we see and touch.  This gives the look of karat gold at a much cheaper cost.

Is The Gold Only On One Side Of The Metal?
The placement of the sheet of gold over the base metal is called "cladding".  There is single-clad gold filled, and double-clad gold filled.  Double-clad is used on items to prevent discoloration (oxidation or tarnish).  Round gold-filled wire and tubes have a layer of karat gold welded entirely around the outside. 

How Thick Is The Gold Layer?
Most gold filled products have an outer layer of gold that is between 10 karat and 18 karat in fineness, 14k the most common. Depending on the usage, the thickness of the gold sheet varies.  The layer is measured in microns, and for reference, 1000 microns= 1 millimeter (and 25.4 millimeters to an inch).  The thickness of the layer of gold in gold filled jewelry is between 5 and 100 microns.   In inches, 5 microns = 0.000196850394 inches.   In inches, 100 microns is 0.00393700787 inches.  VERY, very thin.

What Are the Marks On Gold Filled Jewelry? 

All items designated and sold commercially as “gold filled” or “rolled gold” must comply with the rules set forth by the Federal Trade Commission (FTC).  The total gold content for an object designated "gold filled" must equal 1/20th of the total weight of the finished item.  This means that 5% of the item must be karat gold, and the remaining 95% is the base metal and solder. 

How Long Can Gold-Filled Jewelry Last?
Based on normal and reasonable wear parameters, the durability estimates per Metal Arts Specialties for some gold filled pieces are:

        ITEM             THICKNESS                   EST. DURABILITY
 
Bracelet                    30-75 microns                     5-10 Years
Chains                      5-10 microns                       2-8 Years


What About Gold Vermeil Items? In Comparison, How Long Will It Last?
Based on normal and reasonable wear parameters, the durability per Metal Arts Specialties for some gold Vermeil pieces, which by law must have a minimum of 2.5 microns of gold, are:

      ITEM                THICKNESS                    EST. DURABILITY

Bracelet                  2.5-8 microns                        3-7 Years
Chains                    2.5 microns                            3 Years

✦✦ Please keep in mind that Vermeil is a term used ONLY for solid Sterling Silver (or fine silver) with a minimum layer of 2.5 microns of gold, often 18k Gold or 24k pure Gold.  This means that with Vermeil jewelry, you are getting all precious metals---gold and silver--- which have intrinsic value, and not clad base metal like what you get with gold filled (which is 95% base metal).

What "Myths" or Exaggerations Are There About Gold Filled Jewelry?

• "Gold Filled is considered a lifetime piece of jewelry".  Not really.  It should last, under normal wear, between 2 and 20 years.  SOLID gold is a lifetime piece of jewelry. 
• "Gold Filled is a tube of brass that's filled with gold."   It's not anything "filled with gold".  "Rolled Gold" or "Gold Clad" are other terms, and they are less confusing.
• "Gold Filled will NEVER chip or break off."   Not usually, but it can and sometimes does peel off the base metal.
• "There is over 100 times the amount of gold in gold filled v. gold plated vermeil jewelry, which is just paint."  FALSE!  FALSE! FALSE!  Vermeil isn't "gold paint" and is regulated by the FTC for a minimum of 2.5 to 8 microns of actual gold.   Please refer to the chart above.
• "Gold filled Jewelry will NEVER tarnish!"  Not true.  It can darken with exposure to sulfides in the air or skin, just like other metals.  It can easily be polished back to its original shine.  BUT since there is no such thing as "gold filled solder", the solder joints will blacken and will stand out against the gold filled piece.
• "This cast charm is Gold Filled."  NO.  Gold Filled items can only be made from sheet, wire or tubing due to the nature of the process to make gold fill.  Casting requires melting metal, and gold fill cannot be melted and cast.
• "This ring is Gold Filled."  Unless it's a wire-wrapped ring, made out of gold-filled wire, it is not gold-filled.  If it's a ring with prongs (or a cast ring), it is NOT gold filled and is probably just plated.  It's impossible to melt and cast gold-fill.

Summary
Gold fill is a reasonably priced, quality alternative to solid gold. Most gold-filled items are made in the USA.  Gold filled jewelry will provide the look of solid gold, and the feel of solid gold, for many years.  However, if you are looking for a lifetime piece of gold jewelry, solid gold is the way to go.