How much Gold is in a piece of Jewelry and How much is it Worth?
There are 2 major factors that determine the value of a piece of Jewelry.   One is the value of the Gemstone
if the piece contains a stone and the other is the value of Gold, Silver or Platium contained in the piece.
The following provides information that is helpful in determing the value of the metals.   The value of any
Gemstones will depend on many other factors not covered here.
The Troy Ounce and the number of Grams within an Ounce
Precious metals such as gold and silver are often sold by the Troy Ounce.   Many people donít realize that an
Ounce of Gold (and other precious metals) is weighed in a different weighing system called 'Troy Weights'.
A Troy Ounce is more than the typical ounce found at the grocery store.   In many English speaking countries
there are two systems for measuring weight.   One, for precious metals, called the troy ounce.   The other is
for Commodities such as sugar, grains, and the typical grocery items.   It is called the 'Avoirdupois' ounce.
The Dollar value of One Gram of Gold
Regardless of the Gold Karat rating (10k, 14k, 18k or 24k) that a particular piece of Jewelry has, the piece
will contain a certain amount of Gold.   If the number of Grams of Gold that a piece contains is known, then
the 'Raw' value of the Gold can be determined by taking the current price of Gold times the number of Grams.
Following is information and an example of how to calculate the value:
The 'Troy' ounce contains 31.103 Grams
Therefore, if the current price of Gold is $625.00 per Troy Ounce, then 1 Gram is   worth   $20.04   (625.00/31.105)
Then the 'raw' value of Gold in a piece of Jewelry that contains 5.5 grams of Gold is worth $110.22   (5.5 x $20.04)
Of course, the value of Jewelry is more than the actual amount of Gold it contains and the Gemstone mounted.
Factors that increase the value over the current value of Gold includes the labor and material cost of
producing the piece as well as the retail markup.   As a general rule, the retail markup for every gram of
Gold in a Jewelry piece is around $80.00 per gram.
Karats and Gold - What does it Mean?
Karat is a numbering system to indicate the Percentage of Gold in a piece of Jewelry.  It does not indicate the
total amount of Gold in a particular piece.   The total amount of Gold in a piece of Jewelry is dependent upon
the Size of the piece and the Percentage (Karat) of Gold when mixed with other metals when manufacturing
the Jewelry.   A large 10 Karat Jewelry item that is 2 times larger than a 18 Karat item can have more than
twice the amount of Gold than the 18k item.   The Karat system uses the number '24' to represent pure Gold.
Items with less than 100 percentGold are represented by numbers such as 10k, 14k and 18k.
The Percentage of Gold that each represent are as follows:
10k (Karat) is 41.66 percent Gold (10/24 = 41.66%)
14k (Karat) is 58.33 percent Gold (14/24 = 58.33%)
18k (Karat) is 75.00 percent Gold (18/24 = 75.00%)
24k (Karat) is 100 percent   Gold (24/24 = 100.00%)
Pure 24k Gold is a soft metal and therefore may not be desirable for making items such as Rings, especially for
people who perform a lot of manual labor - in fact, an 18k may be too soft for some applications.