When a 270‐kbar shock wave emerges from an illuminated aluminum surface in a vacuum, blue light is emitted. This phenomenon is affected significantly by surface conditions. A chemically formed aluminum oxide surface layer on the metal luminesces brightly for at least 0.64 μsec. Normally oxidized aluminum surfaces luminesce less brightly for a much shorter time (∼0.01 μsec). The effect of nonoxidized material on the phenomenon is shown in that shocked gold does not luminesce. The luminescence from aluminum is attributed to electrons, dragged by the shock (acoustoelectric effect). The electrons reach the aluminum oxide layer and, falling into ionized F′ centers, emit blue light.

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