Strontium occurs in nature in the form of the minerals celestite, strontianite, and brewsterite. Of these minerals, celestite, the strontium sulfate, is by far the most common and is for that reason the principal strontium ore. Strontianite, the strontium carbonate, is more valuable as an ore because of the ease with which it can be converted into the various strontium compounds of industrial usage but is rarely found in quantities large enough to have commercial importance. Brewsterite, or strontium silicate, is comparatively rare and has no present economic importance.

An effective means of extinguishing magnesium incendiary bombs with ground feldspar or feldspar-rich rock has been announced by the United States Geological Survey, Department of the Interior, Washington. The effectiveness of the method has been demonstrated at the Geological Survey laboratories and at the Edgewood Arsenal of the Chemical Warfare Service. The United States Government controls the patent to protect the public interest against price exploitation and misleading or extravagant claims by private companies.