Colored gemstones can be categorized in two primary ways – Genuine and Synthetic.
Genuine - Genuine gemstones are natural gems brought to us courtesy of nature with no interference from humans. Genuine gemstones vary in color and color intensity from stone to stone. They also have different hardness ratings, which require special attention when wearing or cleaning a piece of jewelry. The Gemological Institute of America has developed a colored gem grading system similar to the well-known Diamond grading system.
Synthetic - A synthetic gemstone shares a genuine stone’s physical, chemical and optical qualities. However, they are created in a laboratory type setting. All synthetic gems have a consistent color and color intensity and generally have a higher hardness rating than genuine gemstones.
The most often used synthetic gemstones are oval and/or cushion antique (think of a rectangle with rounded corners) in shape. The gemstones may have a buff top (smooth) or faceted top and, more often than not, are one of the recognized “birthstone” colors.
- Yellow Gold is alloyed with silver and copper. It is the most frequently used type of gold there is. White Gold is alloyed with a large percentage of silver and is therefore more expensive than yellow gold. White gold is highly reflective and not subject to tarnish.
Rose Gold is alloyed with copper and silver.
Ex: 14kt yellow gold is 58.3% gold, 30% silver & 11.5% copper.
14kt rose gold is 58.3% gold, 9% silver & 32.5% copper
By U.S. law, every gold article must have a karat mark. In addition to the karat mark, every piece of gold jewelry should be stamped with a hallmark or trademark of the manufacturer.
Gold-Plated versus Gold Filled
Gold-plated jewelry has a thin layer of gold that has been applied to any base metal item by means of an electroplating (or dipping) process. Gold-filled refers to stock material which is made by combining a layer of gold to a layer of base metal. The thickness of the gold layer will determine the percentage of gold by weight. It may be 5%, 10%, 15% or 20% gold.
Fine silver in its natural state, 999/1000 pure, is almost as soft as gold, too soft an element for practical jewelry. To make it workable, an alloy such as copper is added. The following are the more common silver alloys:
A mixture of 92.5% silver and 7.5% metal alloy Sometimes jewelry made of this metal mixture is marked .925, to indicate that the metal is at least 92.5% pure silver.
Mexican Silver - 90% - 99% pure silver
Coin Silver - 90% pure silver and 10% metal alloy
German Silver or Nickel Silver - A silver white alloy consisting of copper, zinc, and nickel
Vermeil - Sterling Silver electroplated with karat gold