Weighing in on Precious Metals

The term pennyweight originated in medieval England.  Pennyweight is a term commonly used to quantify precious metals such as gold, silver and platinum, particularly by jewelers, dentists, and refiners.  The abbreviation for pennyweight is “dwt”.

Precious metals are also weighed in Troy ounces.  There are 12 ounces in a Troy pound compared to 16 ounces in the common or Avoirdupois pound.

20 pennyweights equal 1 Troy ounce & 240 pennyweights equal 1 Troy pound.

How does this compare to grams?

There are 31.1 grams in a Troy ounce and 20 pennyweights in a Troy ounce. A pennyweight is the equivalent of 1.555 grams; therefore, 5 dwts equal 7.775 grams and 10 dwts equal 15.555 grams.

More Precious Metal Facts

Karat refers to the purity of gold.  24K is the purest form of gold.  It is also described as being .999 fine or pure gold.  In the United States, jewelry under 10K cannot be legally sold as gold jewelry.  The fine equivalents for common karat weights in the United States are shown below:

10K = .417  14K = .585    18K = .750     22k=.916   24k=.999

Gold prices are based upon .999 fine or pure gold.  If the market price of gold is $1200 per ounce, the price for an ounce of  24K would be $1200, 18K would be $900, 14K would be $702 and 10K would be priced at $500.