The Wannenköpfe
Ochtendung, Eifel region, Germany

The Minerals

TRIDYMITE

Tridymite has (just like Cristobalite) the same chemistry as Quartz ... SiO2 ..... but the structure is different. It occurs mostly as tiny colorless tabulars, twinning is common. The most interesting twins are the six rayed trillings or triplets from where Tridymite gets its name. Till about a week ago I was sure I had just only a few Tridymites in my Wannenkopf collection ... in any case not enough for showing in my mineral list. Last week I was photographing little red Rutile crystals hidden in small Sanidine cavities, and .... by accident I discovered a few Tridymite skeletons. Of course I start looking in my Wannenkopf collection for other specimens with little red Rutile crystals ... . and yes ... in some of them I found tiny but very nice Tridymite crystals. Sometimes very hard to notice ... between all these shiny Sanidine crystals ... changing the angle of lightincidence often helps. Accompanying other minerals besides Rutile and Sanidine .... Quarz, Cristobalite, Pyroxene (sometimes green) and Titanite. So ... if you have some specimens in your collection with red Rutile in Sanidine cavities ..... .

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Bulkemstraat 22 6369 XW Simpelveld The Netherlands

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