- 1 Related WebPages
- 2 Information on Types of Gold Plating
- 3 Other Processes
- 4 Video on Soldering Gold Filled Wire and Sheet
- 5 For Further Research
Information on Types of Gold Plating
The following article is from my Newsletter: In the Studio with Nancy, Volume 3 (sign up on my home page). A comparison of gold filled, gold plate, vermeil, gold electroplate, Technibond, gold flash, heavy gold plate, gilded metal and gold overlay.
On quality stamps: in the United States, you are not required to stamp your jewelry with a fineness (quality) stamp. You ARE required to identify it in some manner, though: on a tag, on an invoice or in some other fashion. If you do decide to mark your jewelry, you must also mark, (near the quality stamp), a Federally Registered Trademark. This stands as a guarantee, from the maker, that the quality is as stated. From: The Essential Guide to the US Trade in Gold or Silver Jewelry.
- If you just use the term “gold”, on your jewelry, it must be 24k throughout.
- The minimum fineness for gold in the U.S. is 10k.
- Gold plate can be mechanically or electrically applied.
- “The exact thickness of the plate may be marked on the item, if it is immediately followed by a designation of the karat fineness of the plating which is of equal conspicuousness as the term used (as, for example, “2 microns 12 K. gold plate” or “2µ 12 K. G.P.” for an item plated with 2 microns of 12 karat gold.)” **Quote from the Federal Trade Commission: Guides for the Jewelry, Precious Metals, and the Pewter Industries. Translation: mark the thickness (i.e: 1/20) and then mark the karat (i.e.: 10k) in either order. As a real life example: Rio Grande sells a double clad, 14/20 gold filled metal. It is 14k with the gold representing 1/20th the weight of the metal.
- Karats vs. Carats – Gold fineness is measured in Karats. 24K is pure gold – there are no other metals in it. 18K would be 18 parts gold to 6 parts of another metal. Carats are used for measuring the weight of diamonds and other gem stones. One carat weighs 200 milligrams or .200 grams.
Here are some great quotes from Artisan Plating.com on the difference between gold plating, gold filled/gold overlay: “The most important difference is layer thickness. Items designated as “gold filled” can be up to 200 times thicker than the heaviest gold electroplating…” “Gold filled items are created by using heat and pressure to permanently fuse a layer of karat gold over a less costly base metal…” “Gold electroplating, especially with the advent of super hard plating materials, are widely used on designs which have intricate or complex shapes.”
The following list is organized by: quality in DESCENDING order with number 9 being the thinnest application and 1 the heaviest application of gold. There is also a consideration of quality: what is the underlying material and how well does the gold stay put. This is also reflected in the following list.
9 – Gold Overlay/Rolled Gold
The total weight of gold must be no less than 1/40th of the weight of the piece and less than 1/20th. It must also be marked with the karat. Example: 1/40th 12k Gold Overlay.
8 – Gold Flash/Washed
Gold Flash is 10K gold that is at least .175 microns thick (7.0 microinches).
7 – Gold Electroplate
Gold Electroplate must be 14K gold and be at least .175 microns thick (7.0 microinches).
6 – Gold Plate
Gold plate must be 14k or higher and be at least .50 (20 microinches) microns thick.
5 – Technibond
This is a marketing idea from the Home Shopping Network. It (now) is “.925 sterling silver with a 40-mils-thick outside layer of 18K yellow gold for a look of 14K.” per the HSN. See “For Further Research” below for more information.
4 – Gold Filled/Gold Overlay
The gold present, must be at least 1/20th of the total weight of the item. Karats can be in 10k, 12k and 14k.
3 – Heavy Gold Plate
Heavy gold plate must be 14k or higher and contain 2.5 microns (100 microinches) of gold.
2 – Gilding
Gilding is a surface application of gold that doesn’t involve electricity. It is a process that involves combining powdered gold with mercury and forming a paste. The amalgam (an alloy of mercury and another metal) is applied to the metal and heated until the mercury is boiled off. This leaves only the gold on the metal. Due to the hazards of working with mercury, this type of process is seldom used today. Aka: Fire Gilding, Wash Gilding. See “Depletion Gilding” below.
1 – Vermeil
(Pronounced “vermay”) – Vermeil must be 14k or higher and contain 2.5 microns (100 microinches) of gold over sterling silver. The heavy plating is achieved through electroplating or fire-gilding. If the sterling silver is plated with another metal, such as nickel, before application of the gold, it cannot be considered Vermeil. ***The Code of Federal Regulations 16, Part 23.5.
This process requires an object that contains at least some gold. Through a subtractive process – employing acid and usually, heat – the other metals present are depleted, leaving a layer of pure gold.
Originally, a Korean technique used by the Japanese, Chinese, the Romans and the Greeks. Keum-boo is a technique of applying very thin pieces of gold to another metal. Keum-boo can be used on steel, iron and copper, although, the process is very difficult. Most of the time it is used on either fine silver or sterling silver that has been depletion gilded. The process requires heat and burnishing.
In this process – employing a similar process to Depletion Gilding – an object containing silver, gold and copper is etched in oxalic acid (to name one type of acid used). The acid only removes the copper leaving a metal that is composed of fine silver and gold. The amount of gold present varies.
Video on Soldering Gold Filled Wire and Sheet
Please see this video from Rio Grande on soldering with Gold Filled metal and wire.
For Further Research
- Artisan Plating.com
- Essential Guide to the U.S. Trade in Gold or Silver Jewelry
- Ganoksin – Article: “Some Notes on Depletion Gilding“ by Charles Lewton-Brain.
- Ganoksin – Article: “Keum-boo” by Charles Lewton-Brain.
- Halstead Bead Blog: “5 Things You May Not Know About Gold-Filled“
- Technibond – “Paul Deasy Spills the Beans about Technibond“, by the Home Shopping Queen.