Abstract
IN a recent paper (Rec. Geol. Surv. India, 1925, vol. 58, pp. 330–337) Dr. L. L. Fermor proposes for glauconite a formula analogous with that already given by Clarke, which I had regarded as inadmissible (Min. Mag. 1922, vol. 19, pp. 330–333). Dr. Fermor's conclusion is based on the fact that the mean of the glauconite analyses agrees with this formula. But, as he himself shows, the composition varies widely. Indeed, it would be equally logical to derive a rational formula from the mean of the published analyses of plagioclase. Dr. Fermor concludes: “It must be pointed out that … the formulæ given are based on averages, and that many of the individual analyses depart considerably from these formulæ”. It was exactly for this reason that I felt compelled to reject the formulæ in question infavour of one which agrees almost perfectly with nine out of the twelve analyses available for this rather obscure mineral.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
HALLIMOND, A. The Constitution of Glauconite. Nature 117, 453 (1926). https://doi.org/10.1038/117453d0
Issue Date:
DOI: https://doi.org/10.1038/117453d0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.