Base Metal... is a catch-all term in the jewelry industry for metals used in costume jewelry. In metal working, base metal is any metal that is not one of the noble or precious metals. Base metals may be plated or raw (bare, unplated). In costume jewelry, base metals are often plated with a very thin layer of gold, silver, nickel, rhodium or other metal on the surface of the bead, finding, chain or other component.
Gold…is a primary metal. Which means that pure gold consist of nothing but gold atoms. Gold in its natural appearance exhibits a vivid luster, but the nugget itself is exceptionally soft. Another characteristic of gold is that it can be easily fashioned with proper tooling. Unfortunately pure gold is far too soft of a material to ever be used in making jewelry, simply put; it could never withstand the rigors of daily use. Instead the majority of today’s jewelry is made from a mixture of metals that’s referred to as “gold alloy”. Alloys are an amalgamation of any two metals. Gold alloys are a combination of pure gold and most often silver, copper or tin, hence 99.9% of gold jewelry created today is from a gold alloy of some type.
Labeling Gold Karats…the Karat classification is employed in calculating gold content in the United States. Pure gold is classified as 24K gold, this is the highest classification in the Karat System and there are no such CLASSIFICATIONS as 25K, 26K and 28K Gold, anyone endeavoring to market or advertise to you these classification, is a corrupt merchant that is using his or her knowledge to steal form you, the uninformed consumer. Karat refers to the number of gold parts verses the number of other metal parts in the gold alloy. A 10K Gold item contains 10 parts gold and 14 parts of another metal to equal (24k). 18k = 75% Gold, 14k = 58.3 % Gold, 12k =50% Gold and 10k = a total of 41.6% Gold.
Gold Plated Jewelry…Plated jewelry contains a base metal most often these base metals are steel, copper or brass, these metals now have a thin deposit of gold applied to the top. Thus the actual “gold” value applied during the plating process is mostly less than enough to actually be stamped with a karat weight, regardless of actual karat weight being used in the plating process. (12k, 14k, etc.)
Gold Filled Jewelry…is manufactured by applying one or more sheets of solid gold 14K, 12K, etc. and enfolding them under compression onto a base metal to be used in the making of jewelry. Hence the gold sheets are now successfully “filled”. Gold filled jewelry will often have a quantifiable volume of gold in it. There are items where the weight of the gold is actually stamped due to its higher content, of measurable gold. In the case of a 1/20 12K Gold Filled marking it would mean that 1/20 of the gold weight of the item consists of 12K Gold.
Silver...It is like “Gold”, in that “Silver” is also a primary metal and pure silver consisting of nothing but silver atoms. Silver alloys are created by combining pure silver and another metal, the most common one used in the manufacturing of quality jewelry today is “Sterling” silver. This silver consists of 92.5% pure silver and 7.5% of some other metal in most cases it is copper, however on occasions zinc will be used in place of copper. The preferred grade of Sterling silver used in the making of fine jewelry is 92.5% pure silver. Hence the mark would be “.925” which is used to designate the level of sterling silver used. For the simplification of explanations you can replace the word Gold, with the word Silver in most categories, i.e. “Filled (Gold/Silver) Jewelry” “Plated (Gold/Silver) Jewelry”. One exception is Nickel Silver which is defined by an array of different names. Unfortunately to an inexperienced consumer the appearance is frequently mistaken for silver. But be sure of this, Nickel Silver has NO silver in it. Nickel Silver is a metal alloy which is created by combining copper, nickel and other metals. This alloy is used extensively in the manufacturing areas of Latin American and Mexico. Most of this jewelry is sold by vendors to sightseers and vacationers visiting their areas.
Important, terms like finished or toned, simply mean that the item/items being described have had their color painted or dyed onto them and that piece itself has no real gold or silver in them.
Gunmetal... also known as red brass in the United States, is a type of bronze – an alloy of copper, tin and zinc. Proportions vary by approximation but 88% copper, 8–10% tin, and 2–4% zinc is an approximation. Originally used chiefly for making guns. Gunmetal varies in color from gun blue to matte dark gray to shiny black metal.
Copper... is an elemental metal that is bright reddish-orange in color. It's a very reactive metal, meaning over time, it will darken and gain a patina, sometimes with a greenish hue. Copper can also discolor skin, most commonly when it is worn snugly like a finger ring or tight-fitting bracelet. Copper is a soft metal, which makes it great for wire wrapping. Because of copper's softness, solid copper components may bend easier than copper-plated beads and findings. Unplated copper is usually called raw copper or bare copper.
Rhodium... It is the most expensive of all precious metals. It is a hard, silver-colored metal that is very stable and has a high melting point. Rhodium metal is resistant to corrosion and, as a PGM, it shares the group’s exceptional catalytic properties. The metal has a high reflectance, is hard and durable, and has both a low electrical resistance as well as a low and stable contact resistance. Rhodium is the rarest of the platinum group. Rhodium is one of the of the six platinum group metals: platinum, palladium, rhodium, osmium, iridium and ruthenium.