Q -1

Basic calculation of Q for resonant LC tanks

Parallel RLC
Q= Rp/|Zp(wo)|

Series
Q=|Zs(wo)|/Rs

More facts:
|Zp(wo)|=|Zs(wo)|=SQRT(L/C)
This ratio is also known as the characteristic impedance of the tank.

This makes sense because we want Rp high or Rs low to minimize the loss.