Confused by Carats vs Karats? Are they the same? Are they different? Do they have anything to do with rabbits?
Ok - Carat with a C is a weight - it is what diamonds come in.
Karat with a K is a measure of purity for gold. 24 Karat is pure gold, 18 Karat is 18 parts gold and 6 parts other metal. Which metal it is makes a difference to the colour. Copper will give you a warmer colour, silver will give you a cooler colour, etc.
How to remember this?
Think of Diamonds and the famous "4 Cs" Colour, clarity, cut, carat.
Karat is then the other one.
You would then have a 1 carat diamond in an 18 karat gold setting. And if you got one of those for Christmas - congratulations!
As for the origin of the word - carat comes from Carob, which were the beans used on a scale as the measure of weight. Nothing to do with snowman noses. ;-)