The first chapter of Ashcroft and Mermin's Solid State Physics discusses electromagnetic waves in metals. One of the exercises requires calculation of the plasma frequency. For iron, I got 11.5 for the angular frequency (radians per second). This seems to low. Is it?

$\omega_p^2=\frac{4\pi n e^2}{m}$ where n is the density of charge carriers, e is the electron charge and m is the electron mass. The authors seem to be using gaussian units although this is not entirely clear. For n I used $1.7*10^{23}\:cm^{-3}$

My cyclotron frequency for a magnetic field of 10 kilogauss, $1.76*10^{11}$, seems to be right.