We report magnetic diffraction of X-rays in the 100 keV region with pe
netration depths of several mm. For the first time a purely magnetic s
ignal could be observed at these photon energies. We obtained 1400 cou
nts/s for the magnetic 300 reflection of MnF2 with a resolution in rec
iprocal space of 1 . 10(-3) angstrom-1 longitudinal and 1 . 10(-4) ang
strom-1 transverse. A proof for the magnetic origin of the signal is p
rovided.