Richard L. Squires
Division of Geological and Planetary Sciences
California Institute of Technology, Pasadena, CA 91109
Alstonite, CaBa(CO3)2, has been identified as coatings of pyramidal crystals onveins of mixed carbonates in specimens of barium and calcium carbonates frm the Minerva mine a Cave in Rock, Illinois. This represents the first recored American occurrence of this mineral. It is biaxial negatife, Nα = 1.526, Nβ = 1.671, Nγ = 1.672. Infrared spectra, X-ray powder diffraction data, and emission spectrographic data are reported.
Infrared spectra of alstonite and other barium and bariuim-calcium carbonates