Romanèchite mineral

Romanèchite is a barium-bearing manganese oxide mineral with the IMA formula (Ba,H2O)2(Mn4+,Mn3+)5O10. The September 2026 list marks it approved (A), with "1982 s.p." in the number/year column; special-procedure notation is not a YYYY-NNN accession. The Handbook describes its monoclinic crystal structure. Romanèchite is a mineral species, distinct from barium or manganese elements, cryptomelane, and mixed manganese ores. The historical collective term psilomelane is not treated as an exact synonym for a pure mineral species. No constituent commodity's criticality is inherited. Pracejus's September 1989 thesis supplies mixed-ore experimental context rather than an accepted romanèchite-specific microbial mechanism. Section 5.5 correlates calculated normative mineral proportions of Groote Eylandt cemented pisolites with results from an Enterobacter-species leaching series. Appendix I.3.2 describes 1.89 g heat-sterilized ore, 8 mL 1% w/v molasses, incubation at 32 degrees C, and weekly concentrated H2SO4 addition before centrifugation and supernatant AAS, followed by fresh molasses and bacteria for a 21-week series. The normative romanèchite calculation allocates barium to this phase and neglects its variable potassium, intergrowths and other potential hosts; it is not a direct time-resolved phase abundance measurement. Figures 5.12-5.13 therefore cannot establish a pure-romanèchite bacterial dissolution yield. Matched uninoculated and acid-only results are not presented in the inspected leaching methods, figures or Appendix V.2. The record retains this experimental relevance without assigning a species/strain CURIE, microbial necessity, mineral-specific rate, isolated recovery, or industrial use.

Record source: data/records/romanechite.yaml