Experiments on the Displacement of the Ultraviolet Absorption Edge of Olivine at High Pressures

The effect of pressure on the fundamental excitation energy of valence electrons in the ferromagnesium orthosilicate, the mineral olivine, is of interest in the theory of the electrical conductivity of the earth's mantle. The experimental determination of this by observation of the displacement of the ultraviolet absorption threshold of olivine up to pressures of about 30 000 bars is described.