Metals

In this section:

Gold, Gold fill, and Gold plate
Why is it Called Sterling Silver?

Gold, Gold fill, and Gold plate

Gold

When people want to tell you something is worthwhile they'll say, "It's as good as gold." But, how good is gold?The question of quality would depend on its purity. In its pure state gold is a metal with a specific color, weight, and luster. When alloyed with other metals the amount of gold is referred to as "karat" or "fineness". Karat is a system for measuring gold based on a 24 point scale of purity. Therefore, pure gold is 24 karat gold or .999 fine. Gold of this purity is too soft and malleable to make durable jewelry so most high quality jewelry is generally made of 22 karat gold (.918 fine) or 18 karat gold (.750 fine) which will stand up to normal wear. In America the industry standard for jewelry is 14 karat gold (.585 fine). Because of its natural softness, gold is normally alloyed or mixed with small amounts of silver and copper to make it more durable. The percentage of silver and copper that is alloyed to the gold affects its color and hardness. If the silver and copper are used in equal parts, the resulting metal is predominantly yellow, when more silver is used the result is a slightly greener gold and when more copper is used the gold has a rich red color. When gold is alloyed with nickel or palladium rather than silver and copper it produces a rich white metal otherwise known as White gold which is very hard and polishes beautifully.

Gold Fill

"Gold fill" is a method by which a thin foil of gold is bonded by heat and pressure to a core of brass. In the case of gold filled wire, the gold foil surrounds a brass core while gold filled sheet metal on the other hand may be gold clad on either one or both sides. The gold becomes a fairly durable layer that will last for many years provided the metal does not encounter heavy wear or chemical contamination. The layer of gold must be 1/20th or 5% of the total weight of the metal. A quality mark of 14/20 GF should be read as meaning 5 % of the metal is 14 karat gold. This provides the look and feel of karat gold at a fraction of the price.

Gold Plating

Gold plating is primarily an electrical process. First a piece of base metal, normally brass, is submerged in a plating solution and then an electric current is passed through both the solution and the item being plated. There are many different solutions depending on the amount and color of gold to be plated. This process moves individual atoms of gold out of the solution and onto the item being plated. The gold plate is thus evenly deposited only a few molecules thick over the entire object. Depending on various factors, this coating can be worn away in a very short time or last quite a while. Please do not consider plating as a hobby as the process is much more complicated than this simple description makes it seem and the solutions involved contain highly corrosive acids and deadly chemicals like hydrochloric acid and cyanide.Hopefully this article helps to clear some of the confusion around gold and make you a more educated consumer when purchasing findings, metal beads and other materials containing gold.

Bibliography

Professional Goldsmithing by Alan RevereJewelry Concepts and Technology by Oppi UntrachtNotes from goldsmithing classes by Beverly Fernandes

Why is it Called Sterling Silver?

The term "sterling silver" probably originated in eastern Germany when five towns formed the Hanseatic League in the 1100s. These town minted their own coins of 92.5 percent silver. When Britain sold cattle and grain to the League, they were paid in "Easterling coins". These coins were found be reliable and durable and soon became the standard for subsequent British coins. King Henry II decided to adopt the standard 92.5 coins for Britain's own currency.He imported both trained metal refiners and their equipment from Germany to England. Henry set up a royal mint to produce easterling silver coins now known as "Tealby Pennies". The term easterling silver was quickly shortened to sterling silver.Pure silver is a very soft metal that is easily formed and deformed. Most silver used today is alloyed with small amounts of copper. The addition of copper makes the silver more robust and workable. The term sterling silver refers to a specific alloy of silver and copper. Manufacturers use a variety of recipes when producing various forms of silver. Fine silver is 99 percent silver and the remaining 1 percent is a combination of copper, iron and other trace elements. It is extremely soft and not generally suitable for jewelry. Its main use today is in fine silver coins to be used as a trading commodity.Britannia Silver was 95.8 percent silver and used for flatware and plate between 1697 and 1720. However, it was found to be to unsuitable due to its softness, as it tended to deform under its own weight.Mexican Silver is 95 percent silver and 50 percent copper, but Mexico no longer mints .950 coins. Old Mexican coins are still found and used to make jewelry.Sterling silver is 92.5 percent silver and 7.5 percent copper. It is more durable and workable than fine silver. In Britain, sterling silver is better known as 'Standard Silver'. This term refers to the fact that British coins from 1158 to the 1920s were 92.5% silver. Today British coins no longer contain 92.5% silver.Coin silver is an American term for silver that is 90 percent silver and 10 percent copper or other metals. Most American silver coins used this alloy from the 1820s when silver coins were a standard form of currency. It was also used to mint the coins in the American territories of the Philippines and Panama.Continental Silver can be found in Europe, this alloy is 83 percent silver and 17 percent copper or 80 percent silver and 20 percent copper. It is commonly used for flatware (tableware) and hollowware (vases and picture frames).All of these alloys were accepted as standard formulas in 1972 by the nations that signed the Vienna Convention. This convention set international standards for articles made of precious metals They also agreed on standards for hallmarking these items for the public.

Bibliography

Jewelry Concepts and Technology by Oppi UntrachtProfessional Goldsmithing by Alan RevereNotes from Metalsmithing Classes by Beverly Fernandes