Magnesiohögbomite-2N4S, a new polysome from Antarctica: structural formula of högbomite group minerals

Abstract

A new polysome magnesiohögbomite-2N4S was found in the Sør Rondane Mountains, Antarctica. The samples were collected during the geological field survey as the 50th Japanese Antarctic Research Expedition (JARE-50). The högbomite is formed by the sequence NSSNSS. If we use the module numbers n and s, and an exchange parameter "x" (0 ≤ x ≤ 2), a general formula for the högbomite group can be written as: R²⁺_n+2s-x R³⁺_3n+4s+2x R⁴⁺_n-x O_7n+8s (OH)_n .