  We introduce semiclassical methods into the study of the volume spectrum in
loop gravity. The classical system behind a 4-valent spinnetwork node is a
Euclidean tetrahedron. We investigate the tetrahedral volume dynamics on phase
space and apply Bohr-Sommerfeld quantization to find the volume spectrum. The
analysis shows a remarkable quantitative agreement with the volume spectrum
computed in loop gravity. Moreover, it provides new geometrical insights into
the degeneracy of this spectrum and the maximum and minimum eigenvalues of the
volume on intertwiner space.
