Polytypism of cronstedtite from Nagybörzsöny, Hungary

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F20%3A10135261" target="_blank" >RIV/00023272:_____/20:10135261 - isvavai.cz</a>

Alternative codes found

RIV/68378271:_____/20:00539368

Result on the web

<a href="https://link.springer.com/article/10.1007%2Fs42860-020-00102-9" target="_blank" >https://link.springer.com/article/10.1007%2Fs42860-020-00102-9</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s42860-020-00102-9" target="_blank" >10.1007/s42860-020-00102-9</a>

Result language

angličtina

Original language name

Polytypism of cronstedtite from Nagybörzsöny, Hungary

Original language description

The present study provides an example of the accurate identification of polytypes of trioctahedral 1:1 layered silicates from single-crystal X-ray diffraction data collected with the aid of a four-circle diffractometer equipped with an area detector. Single crystals of the mineral cronstedtite from the Nagybörzsöny gold ore deposit, northern Hungary, were studied. The chemical composition of some crystals was determined by electron probe microanalysis (EPMA). The precession-like images of the reciprocal space (RS) sections created by the diffractometer software and presented in the study were used to determine the OD (ordered-disordered) subfamilies (Bailey&apos;s groups A, B, C, D) and particular polytypes. With one exception, all crystals studied belong to subfamily A. The rare polytype 1M, a = 5.51, b = 9.54, c = 7.33 Å, β = 104.5o, space group Cm is relatively abundant in this occurrence. Another polytype 3T, a = 5.51, c = 21.32 Å, space group P31 was also found. Both polytypes occur separately or in mixed, mostly 1M dominant crystals. Some 1M polytype crystals are twinned by order 3 reticular merohedry with a 120o rotation along the chex axis as the twin operation. A rare 1M+3T mixed crystal with 1M part twinned also contains a small amount of subfamily C. A possible presence of the most common 1T polytype of this subfamily cannot be confirmed because of overlap of the characteristic reflections with those of 3T. Several completely disordered crystals produced diffuse streaks instead of discrete characteristic reflections on the RS sections. The EPMA revealed Fe, Si, traces of Mg, Al, S, and Cl. One black crystal originally considered to be cronstedtite was identified as (111) twinned sphalerite. Some crystals of cronstedtite are covered partially by a honey-brown crust or small crystals of siderite.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10504 - Mineralogy

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Clay and Clay Minerals

ISSN

0009-8604

e-ISSN

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Volume of the periodical

68

Issue of the periodical within the volume

6

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

632-645

UT code for WoS article

000593003800001

EID of the result in the Scopus database

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