Gold is usually stamped 375 for 9 carats, 585 for 14 carats 750 for 18 carats, 875 for 21 carats and 9999 for 24 carats. Where do these numbers come from and what do they mean.
The three digit numbers are the ratio content of the gold over 1000, so for example:
375/1000 = 37.5% gold
The carat measure is over 24 where 24 carat is 100% gold. For example:
37.5% X 24 = 9 carats
87.5% or 875 is 87.5% X 24 = 21 carats
To convert from carat to percentage use the following formula:
Carat / 24 x 100 or
Carat / 24 x 1000 to get the three digit stamp number
To convert from the three digit number to carat use:
Three digit number /1000 X 24
Now pure gold is stamped 9999 which is 999.9/1000 = 99.99% gold.
How do you calculate the scarp gold value for your gold?
If you have 21 carat gold jewellery then it contains 87.5% gold, so let's say it weights 10 grams, then 10 X 87.5% = 8.75 grams of pure gold is present in it.
If the current market price of gold is $1400 for example and that is the price per ounce. A gold ounce refers to a troy once (ozt) which is equivalent to 31.1034768 grams, a standard ounce is usually 28.3495231 grams but a gold ounce is different. A troy ounce comes from the Roman monetary system.
In our piece of jewellery above 10 grams at 21 carat, it contains 8.75 grams of gold.
1 gram is worth $1400/31 = $45
So 8.75 grams are worth 8.75 X $45 = $395
So the formula is:
Weight in grams X three digit stamp / 1000 X ounce market value / 31 = dollar value of scrap gold
Try the online calculator if you can't be bothered using a manual calculator:
Online GOLD PRICE CALCULATOR
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