Not all Gold is of the same value but what is pure and why does it matter?
Pure Gold is never plated or filled jewelry you can put on a scale and do the math to understand exactly how much gold you have. If it weighs 17 grams, then you can say you have 17 grams of gold.
What are the other options?
Plated or filled gold jewelry, but it is not pure gold. It is a cheaper metal with gold paint, essentially. A 17 gram chain is likely to have about 1/10th of gram of gold or less. Melt it down and you will find 16.9 grams of actual gold. All the value is in the craftmenship and none in the gold.
Plated and filled gold jewelry is simply another type of jewelry like stainless steel, nickel, copper and then it has a thin coating of gold on the outside. Filled is thicker than plated and will last longer however regardless of the method, it is still just a really nice piece of steel with a good paint job.
So pure gold is exactly that, pure gold but there are different grades of gold and that is referred to as karats. 24 karat gold (24k) is the true pure all natural, no other elements but “Au” the element of gold. It is widely considered to be 99.99% Gold.
24k will never rust, never change and will last forever however, it is very soft. You may have seen some old movies where miners were picking up gold nuggets and biting them to see if it is real gold and that is because it was softer than teeth, you really can make an impression it is so soft. Long gone are the days of miners finding big nuggets on the river side.
To make durable intricate jewelry the gold is mixed with silver, nickel, copper, zinc or titanium. The additional alloys produce colours such as rose gold, brighter yellows or white gold. Additionally, these other elements provide strength, durability and in some cases mailability for finer smoother mirror like polishes that sparkle.
When the alloys are mixed the jewelry is stamped with whatever the content is, 10k, 14k, 18k, 21k 22k or 24k Gold.
Pure Gold Jewelry means that the alloy is 100% the same, it is pure. If it is stamped 18k, you know with 100% certainty that the jewelry is a 75% gold alloy mix. Never plated or filled over lesser quality metals. You can put it on a scale and do the math to know exactly how much gold you have.
