Gold-Filled: Five Things You May Not Know

Gold Facts

Most people do not have any idea what gold-filled jewelry is yet we all spend our hard-earned dollars on gifts for our loved ones not knowing whether the gift item we purchased is gold-plated, solid gold or plastic-covered with gold plating. With so many different scams on the go, perhaps it would be wise to take a refresher course in gold-filled jewelry: five things you may not know.

When gold is taken from the earth and separated from impurities by smelting in the furnace, it is very soft, pure gold called 24 karat. Miners of placer gold found in rivers and creeks are able to tell how far from the source the nuggets have traveled from the mother lode by the absence of sharp edges. As the nuggets bump along the creek bed the sharp edges are rounded off.

  1. Solid gold 24k is never used to make jewelry. The gold must be blended with other minerals such as copper, nickel, silver or platinum to create durability. Without these hardeners, the items would wear down very quickly.
  2. Another gold standard referred to as solid gold may be 18k or 14k. This means that the 18k gold consists of 18 parts gold and 6 parts other metals; likewise for 14k. 10k gold products are simply called 10 karat gold, consisting of 10 parts gold and 14 parts other metals.
  3. Gold-filled products are created from a plate of 10k, 14k or 18k gold being fused to another plate of precious metal such as copper, brass, silver or platinum. It may be in the shape of a tube with the inside consisting of the other metals and the outside, gold. The other metals help to harden the gold and should last for 20 to 30 years or more before it shows signs of wearing through.
  4. Gold-plated products of different qualities may be manufactured by way of electroplating. This is done by attaching the pieces to be plated to one side of a battery and attaching the other side of the battery to a piece of gold and immersing both into an acid bath. This allows the gold from the anode to transfer to the goods to be plated. In the United States, the quality of gold-filled jewelry is defined by the Federal Trade Commission. If the gold layer is 10k, the minimum weight of the gold-plated layer on an item stamped GF must equal at least 1/10th of the total weight of the item. If the item is stamped GF with 12k or more, it must contain at least 1/20th of the total weight of the item.
  5. So what then do we call an article that is stamped 10k or 14k? It is not gold-filled nor is it gold-plated. This is where things get confusing, 10k gold is made up of 10 parts gold and 14 parts other metal. The item is 10k gold all the way through. To make matters more confusing, 14k gold is sometimes referred to as solid gold.

Next time you visit your jeweler, try to remember some of these points so that you may make the right choice of that gold gift.

How is Gold Found?

found it golden nuggets gold pan in the water

Prospectors search for gold by traveling along streams and panning for gold at every little bend where sand and gravel pile up. They partially fill the pan with material and water and wash the gravel by swishing the pan back and forth and slowly allowing the large stones to fall away. As these stones are removed the pieces of gold, which are much heavier than the sand, will gather at the bottom of the pan. If there is no gold to be seen the prospector will move along. If he spots a few tiny flakes of gold, called colors, he may decide to work the area for more.

The Rocker

A rocker, also called a “cradle” or a “dolly”, is used when water is in short supply or when the depth of the stream or creek is too shallow to use a sluice box. The principle of the rocker is simple: As the cradle is rocked, water washes the finer material through the bottom of the hopper and gold collects on ridges or riffles. Rockers were used extensively for placer mining. With one man to load soil and water and a second to rock it, the rocker could process about 200 buckets per day.

The Sluice Box


The sluice box is a long, open wooden trough and when it was introduced it became very popular. The sluice is narrow and low at one end. Dirt and gravel is placed at the top and washed down the length of the sluice by a constant stream of water, usually from a flume. Gold would be caught either by “riffles” (ridges on the bottom of the sluice box) or by a false bottom with holes in it. Mud and the larger chunks of rock would wash out the lower end leaving the gold behind.

This was the method used back in the 1850s.

These old-timers would leave civilization and head for the hills, spending many months on the streams usually with very little to eat. If their search proved successful, they would need to travel to the nearest gold commissioner’s office where they would file a claim for the rights to dig for gold. They would be given tags to be put on the markers to be placed in the corners of their claims. Once the task was completed, they would get to work.


Over millions of years the gold erodes from the rock and quartz bit by bit. As it is heavy it washes out of the gravel and settles down to bedrock. Since bedrock is solid, the gold cannot go down any further so that is where it remains to be found sometime in the future. As the streams and rivers are continually moving back and forth across the valley floors, new flakes and nuggets are moved with the action of the water and glaciers along with the sand and gravel. Prospectors know this and will search for high banks where once upon a time the water flowed. Some of the gold will generally remain in the deposits of these banks.

The prospectors will be searching for what were old stream beds that have gone dry. Although panning for gold appears to be a long forgotten system it is still the best tool for prospecting for gold in the right hands.

Once a claim is set up, the hard work begins.

Way back when, the miner would begin to dig and either sluice or rocker the gravel he excavated. Today the owner will probably get some backers with the money and set up large sluice machines that are capable of sluicing many tons of gravel per day. The sluice will be fed by a large backhoe or loader that may be assisted by use of a bulldozer. The water supply will be pumped to the sluice and a series of riffles and metal mats will capture the gold as the water washes away the sand and gravel.

This method is employed to carry out placer mining. This method will be used to dig down until the bedrock is uncovered.

Generally the cleanup will be done every 20 or 30 hours of sluicing. The sluice machine will be shut down and the mats and riffles will be shoveled by hand into buckets or tubs. Every little speck must be captured. The gold will be taken to the refinery where it will be melted down and poured into a mold.

Hardrock Mining

Some mining companies employ prospectors to tour the country on the lookout for promising mining sites. When something promising is located, a drill team will be sent in to do some diamond drilling. Cross-section cores will be examined by company geologists to determine the gold content of the site. When the gold content looks promising, plans may be drawn up to make the decision to set up a mine or not.