Answer
Yes
Work Step by Step
Determine the density of the jewelry:
$\text{Density}=\frac{3.17\text{ g}}{0.3\text{ mL}}\approx 10.57\text{ g/mL}$
Compare the density of the piece ($10.57\text{ g/cm}^3$)with the density of silver ($10.49\text{ g/cm}^3$):
Yes, the jewelry could be made of pure silver — the measured density is very close to that of pure silver, within reasonable experimental error.
