My husband bought me a Gold Ring as our wedding ring many years back in Hong Kong. There is an indent marking on the inside of the ring and by using a magnifying glass I can read it as 20K gold. I understand that 20K gold means a pure gold content of at least 83% pure gold.
I brought the gold ring to a local jeweler and he used a ‘gold meter’ to test the content. The meter reading indicated that the gold was as stated.
However, I am still not confident as the weight of the ring seems to be very light to me as compared to other gold rings my family had. I read one of your posting that by hefting (read here) the object, we might get some idea of the weightiness of the jewelry, but I am no expert.
How do I know whether we have been cheated whereby the gold content is not up to the marking as shown? I enclosed a picture for your viewing.
Your input is much appreciated. Thank you
A 20K hallmark on the inside of a gold ring means that the gold content must be equal or more than 83.33% of pure gold content while the remaining percentage can be an alloy of silver, copper or nickel. It is also a standard practice of the jewelry gold industry that a gold ring which is hallmarked as 20K gold should be at least 83.5% of pure gold. The additional small percentage is to make up for some welding joints which may have a lesser gold content to make the joints harder.
Your gold ring does not have any shoulder joints, so therefore, the pure gold content must be at least 83.3%, if what is represented by the jeweler is true.
You can take the gold ring to a Gold Assay Office to have the content assayed, however, this cost money.
Regarding the gold meter testing it may not be 100% accurate. The reason is simple. The Gold Meter works on the principal that gold is an excellent conductor of electricity. By testing the conductivity the meter will show a reading indicating the gold content. However, if the gold coating is thick enough (while the inner content maybe a lead compound) then the meter reading may give you a faulty or fallacious reading.
Since your gold does not have any stones mounted, taking the Specific Gravity (SG) of the ring will be an accurate test to determine the gold content. The SG of gold is 19.3, hence, the SG of your ring should be somewhere around 16. You should make an allowance of 5% margin of error.
Most goldsmiths understand the principal of using SG to determine the gold content. So you can perhaps take it back to a goldsmith jeweler and request him to check the gold content.
I will be putting up a post regarding the use of specific gravity later. You can do it yourself if you have a weighing equipment up to 0.00gm accuracy.
So do look out for that post.