gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1960.032.248.01 A Thermal and X-ray Investigation of Scarbroite Duffin W. J. M.A., Ph.D., A.Inst.P. Goodyear J. B.Sc., Ph.D., A.Inst.P. Physics Department, University of Hull. 3 1960 32 248 353 362 Copyright © 1960, The Mineralogical Society 1960 Summary

Scarbroite, a fine-grained but compact deposit obtained from fissures in the sandstone on the north Yorkshire coast, is shown by chemical analysis to have an idealized formula Al2(CO3)3·12Al(OH)3. X-ray and electron diffraction data indicate a triclinic cell with a 9·94 Å., b 14·88 Å., c 26·47 Å., α 98·7°, β 96·5°, and γ 89·0°. A layer structure consisting of gibbsite-type sheets of Al(OH)3 and sheets of Al2(CO3)3 is proposed. The structure is stable from room temperature to about 125° C.