24k (k for karats) gold is a really pure one and it means that the band is made of a pure metal, which was quite strange for me. I never saw a band made of the pure gold. However, the volume, mass and density are all interrelated to each other as the following expression:
We can also say that it is 0.181 mL or 1.81*10-4 L of possibly displaced water (when the band will be sank in water).
P.S. The jewelry gold metal is always a complicated alloy of gold, silver, nickel and copper.