BMJ Blog

Testing for the Purity of Gold

Posted on October 23, 2014 by Mary Hood | 0 Comments

Usually gold jewelry is stamped with its karat amount, but polishing, repair, and wear can efface the stamp. Fortunately, there are a few reliable ways to determine the karats or your piece.

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Posted in gold, gold purity, informational, jewelry, karat, quality stamp

About Carats, Karats and Carrots

Posted on January 11, 2010 by Barbara Polinsky | 0 Comments

The correct use of the words karat and Carat can be confusing. Both derive from the word carob because carob seeds were used as counterweights on ancient balancing scales. Although other types of seeds were also used for measuring, the carob seed was preferred for its precision in weighing gold and gemstones because its mass varies so little.

Here's a quick overview of the differences:

CARAT is a unit of weight used specifically for gemstones and pearls. One carat is equal to 200mg or 100 points. Therefore, a .70 carat stone may also be referred to as being 70 points. This unit of measurement was adopted by the United States in 1913.

KARAT describes the quality or purity of the gold in and item. Pure gold is 24 karat and is rarely used for jewelry in its pure form because it is so soft and also very costly. Gold is normally alloyed with other metals such as silver and copper and the resulting blend is harder and more durable for jewelry. Reducing the percentage of gold and increasing the amount of other alloys has another added benefit. It reduces the cost and makes the piece more affordable. The lowest karatage that can be sold and marketed as Gold jewelry in the United States is 10 karat.

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Posted in carat, diamond weight, DIY, gold content, Informational, karat