On the relation of chamosite and daphnite to the chlorite group (With Plates XVIII and XIX.)
- 1 December 1939
- journal article
- Published by Mineralogical Society in Mineralogical Magazine and Journal of the Mineralogical Society
- Vol. 25 (167) , 441-465
- https://doi.org/10.1180/minmag.1939.025.167.02
Abstract
There is a close optical and chemical resemblance between chamosite, the chloritic mineral of the bedded ironstones, and daphnite, a low-temperature vein-chlorite common in some of the Cornish tin mines. New material has made it possible to undertake a fresh comparison of the two minerals: chemical analyses have been made by Mr. C. O. Harvey, chemist to H.M. Geological Survey, and a report on the X-ray measurements is contributed by Mr. F. A. Bannister, of the Mineral Department of the British Museum.The new analysis of chamosite agrees with the simple formula previously assigned: X-ray examination of material from several localities has now established the distinctive crystalline nature of this fine-grained mineral, which differs structurally from ordinary chlorites such as clinochlore. Daphnite, on the other hand, has the ordinary chlorite structure, but the new analysis fully confirms Tschermak's original opinion that it cannot be represented chemically as a mixture of serpentine and amesite.Keywords
This publication has 4 references indexed in Scilit:
- Replacement veins in the Mourne Mountains granites, N. IrelandAmerican Journal of Science, 1939
- The Spherulitic Ironstones of West YorkshireGeological Magazine, 1934
- The Iron-Ore Oolites and Pisolites of North WalesQuarterly Journal of the Geological Society, 1933
- On the Chemical Classification of the Mica Group. II. The Basic MicasMineralogical Magazine and Journal of the Mineralogical Society, 1926