Most discerning buyers, when selected a ring, note that they can get a 14K or an 18K gold ring and wonder what the difference, other than gold quantity, there actually is between the two.
The 14K and 18K refer to the amount of gold actually present in the item you’re looking at. Pure gold contains 24K so 18K contains 18 parts gold and 6 parts of some other metal, or 75% gold. 14K gold contains 14 parts gold and 10 parts some other metal. The lowest karat weight for gold in the United States, and for the material to still legally be called gold, is 10K (10 parts gold, 14 parts something else).
The ‘other parts’ is what jewelers use to fiddle with the color. You can get it to be gray by using nickel, you can create white gold by using Palladium, and you can use copper to get a rosy effect.
The only warning about gold and the concept of “more is better” is that 24K gold is usually too soft for jewelry. If you look, you’ll often even see that the settings on an engagement ring are white gold or some other “harder” metal and not 18 or 14 karat gold, just to get additional strength. For jewelry, 18K and 14K gold is strong enough.