Gold Calculations - Definitions, 18K, 14K, 12K, 10K

One of Earth's most remarkable metals is gold. It's combination of unusual qualities, both chemical and physical, make it invaluable in many applications. Gold is immune to the effects of air, oxygen and water, and as such will not tarnish, corrode or rust. Gold has unbelievable ductile and malleability qualities. Imagine - an ounce of gold can be drawn into a wire 5 miles long; or hammered into a 100 square foot sheet.

Gold is widely used in jewelry manufacturer, often combined with other metals for strength or to change its color.

White Gold is an alloy of gold and at least one white metal. The white metal can be nickel or palladium.
Rose Gold is an alloy of copper and gold. The more copper the stronger the effect.
Green Gold is created by adding silver to gold.

The amount of gold in an item can be described in 3 ways:

Karat - parts of gold per 24
Percent - parts of gold per 100
Fineness - parts of gold per 1,000

According to the U.S. Federal Trade Commission Guidelines (Jewelry Industry) the minimum amount of gold in a jewelry item that can still be called 'gold' is 10K. In France, Switzerland and Italy the lowest amount of gold in an item that can be called 'gold' is 18K. England's minimum is 9K.

US Gold Marks
European Marks
Percentage of Gold
24K is pure gold
100% gold
22K is 22 parts gold plus 2 parts other metal
91.67% gold
18K is 18 parts gold plus 6 parts other metal
75% gold
14K is 14 parts gold plus 10 parts other metal
58.3% gold
12K is 12 parts gold plus 12 parts other metal
50% gold
10K is 10 parts gold plus 14 parts other metal
41.7% gold

Test your gold at home with Mizar Gold Testing Kit - from Amazon.
This kit is reliable and easy to use.

Click here for an equation to calculate gold content of jewelry.

The letter 'P' (plumb) following the karat mark on a piece of jewelry (Ex: 18KP) indicates that the piece is no less that what it is stamped. Without the 'P' the piece can fall within a preset range and still qualify to carry the 18k mark.

Gold is weighed in 'Troy Ounces'. One Troy Pound (lb) is equal to 12 Troy Ounces or 373 grams.
One Troy Ounce is equal to 20 Pennyweights (American jewelry trade)
One Troy Ounce is equal to 31.1034768 grams
One Pennyweight is equal to 1.55 grams

Other types of gold designations usually found on jewelry are gold filled, rolled gold plate, and Vermeil. Gold filled is defined as a layer of at least 10K gold bonded permanently to one or more surfaces. Rolled gold plate is a 10-karat or better plating that has been mechanically bonded to the base metal. Vermeil is a sterling silver base that has been bonded with gold at a minimum of 15-micro-inches thick.

Gold bullion and gold coins are quickly becoming a favorite of investors. While bullion can usually be purchased at a percentage above spot value, gold coins that were minted as legal tender money need to be examined for their numismatic value.

If you've been thinking about collecting or investing in gold, visit to see current gold values, gold information and excellent buys.

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