Metallurgy - Do you know your metals?


What is the difference between different types of metals?

For jewelry, silver is used in the form of sterling silver, which is 92.5 percent silver and 7.5 percent copper, also called .925 Silver. Sterling silver is durable and long lasting, which explains why it is a popular. However, silver jewelry is softer than gold, platinum and titanium, and it does require more care than some other precious metals because it tarnishes. Pure silver is .999 silver, .1 percent copper, and is considered the finest silver. A new type of silver is on the market called Argentium Silver and is reported to be easier to work with for Metalsmiths. As such, it is more expensive.

Silver filled metals (also called “silver overlay”) have been popular for years. Silver-filled wire is made by using heat and pressure to apply a layer of silver to a base of less costly metal, such as copper or brass for example. This silver layer is hundreds of times thicker than a standard plating. The thickness of the sterling silver overlay on silver-filled wire constitutes a full tenth of its overall weight. Silver filled components are affordable, long lasting and beautiful.

Gold jewelry is made up of an alloy of gold and other metals, such as silver, copper, nickel and zinc. The actual gold content of metal is measured in Karats (K) or carats (ct), which describes the proportion of pure gold to the other metals in the material. The higher the proportion of gold in the final metal, the more expensive it will be. 

4. GOLD-FILLED - Gold-Filled jewelry have a central core of brass or copper and a thick outer layer of gold. These metals are much stronger and durable than plated metals (see below) and can last a lifetime with proper care. As such, they are more costly than plated metals. 

The following diagram is relevant for silver-filled metal as well. Just insert the word "silver" for "gold":

5. GOLD VERMEIL is plated with 22K-24K gold. The difference between vermeil, and gold-filled, is in the thickness of the gold and the base metal used. In vermeil, the base is sterling silver.

Noble metals are resistant to corrosion, unlike base metals such as nickel and iron which corrode easily. Noble metals like copper and brass make beautiful hammered pieces, and will patina to a beautiful hue. If one prefers the brightness of unpatinated copper or brass, a thin layer of jewelry sealant is recommended, but is by no means permanent.

Copper and Skin Discoloration - People are not allergic to metal; metal reacts to you and your skin, sweat, natural oils, and lotion or perfumes put on the skin. On some people  copper leaves a dark grey discoloration, on others, it may appear green. This discoloration is not permanent (it washes off) and varies from person to person as the copper reacts differently on different people.

Platinum is the rarest and most expensive of the metals. It is incredibly durable and does not tarnish. To enhance its characteristics and durability, platinum is alloyed with copper and cobalt along with "platinum group" metals such as ruthenium, rhodium, palladium, osmium, iridium, and platinum.

8. PLATED METALS - Silver or gold plated metals have a thick inner core of brass or copper and a very thin outer layer of silver or gold. These metals will last years depending on usage, care, storage, and cleaning. Jewelry made with plated metals are very economical. Without proper care the outer layer can wear off in under a year leaving the bare copper or brass core exposed. Some plated metals come with a Rhodium coating from the manufacturer and can significantly increase the life of the metal. Rhodium coated plated metals are more costly.

Choose the type of metal that suits your lifestyle and budget! You won't regret it!