| George R.
Rossman,
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