A low-charge corrensite, i.e., a regular 1:1 interstratified smectite/chlorite was found in veins and fissures of an extensively fractured dolomite south of Perth, Ontario, Canada. Total chemical analysis indicated that the mineral was trioctahedral, having a structural formula corresponding to: (Ca0.17)(Mg7.36Al0.90Fe3+ 0.45Fe2+ 0.42)VI(Si6.06Al1.94)IVO20(OH)10. The coefficient of variation (CV) of the d(00 l ) spacings calculated for the mineral from X-ray powder diffraction data was 0.42, well below the maximum recommended value for corrensite, 0.75. The corrensite coexists with phlogopite, which is present as small (~0.5 mm) crystals throughout the rock and locally as large (~5 cm) crystals in pegmatitic veins. Microscopic observatiofls of large phlogopite crystals partially altered to corrensite suggest that corrensite formed at the expense of phlogopite by hydrothermal alteration.
No takes yet. Share an insight, caveat, or question.
KIMPE et al. (1987) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: