Karat is how much of the piece is pure gold. 24K is pure, 22K is 91.6%, 21K is 87.5%, 18K is 75%.
The higher the karat the softer the metal, so 24K is kept for bars and simple pieces, and 18K is used where the design has to hold a stone or a thin link.
The price of a gold piece is: weight in grams × the rate for that karat today + the making charge + the value of any stones. Nothing else is added.
That is why the same necklace can cost differently in two weeks: the weight did not change, the rate did. Today's rate is on every page of this shop.
