Crystal Structure of Gunterblassite, a New Mineral with a Triple Tetrahedral Layer

摘要

Postmagmatic parageneses of the Eifel volcanic field (Germany) are characterized by a wide variety of minerals [1]. Gunterblassite~1 is a new mineral discovered in a late association formed in the cavities of the alkaline basalt of the Rother Kopf mountain. The chemical composition was determined by electron microprobe analysis. The content of H2O was quantified by chromatographic analysis of gaseous products of calcination. The IR spectrum of the mineral shows the absence of borate, carbonate, nitrate, and ammonium groups. The empirical formula calculated for 13 atoms (Si, Al) is