Karfosyderyt z Koronowa nad Brdą

Stanisław Romuald Krażewski

Abstract


CARPHOSIDERITE FROM KORONOWO ON THE BRDA RIVER

At Koronowo, on the Brda river (near Bydgoszcz) a profile of the Quaternary and Tertiary deposits exposes in a brickyard pit. In the Tertiary clays containing: brown coal interbeddings ferric sulphate belonging to the jarosite group has been found. The results of chemical analyses are presented in Tables 1 and 2 of the Polish text. The chemical investigations have indicated that the yellow ferric sulphate analyzed here is carphosiderite having a chemical formula

(H2O)·Fe3(SO4)2·[(OH)5·H2O]

or a modified one obtained after introducing the (H3O) ion, by N. W. Shishkin as follows: H3O·Fe3[(SO4)2·(OH)6]

Belonging of this mineral to the jarosite group has been proved by an identification X-ray analysis. Differences in the X-ray patterns of individual members of the jarosite group, quoted from the literature data are shown in comparison with the carphosiderite in Table 3 of the Polish text.

The author also discusses objections raised by A. A. Moss and R. van Tassel who called in question the existence of the carphosiderite as an individual mineral. Occurrence of the carphosiderite from Koronowo has confirmed the thesis by N. W. Shishkin and J. Kubish concluding the carphosiderite to exist.

Notwithstanding the objections raised by J. Kubish as for applying the term carphosiderite and replacing this latter by a term "hydronium jarosite", the present author is in favour of upholding the term "carphosiderite", originally used.


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