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PhotosGehlenite - Linyi Prefecture, Shandong Province, China

10th Aug 2014 12:08 UTCErik Vercammen Expert

Siderite, Epidote

Linyi, Shandong, China

On my screen, the angles look like they are not 90°, like it should be for a tetragonal mineral like gehlenite. The crystals make me think of chabazite, or even dolomite or calcite.

10th Aug 2014 13:08 UTCAlfredo Petrov Manager

I agree, Erik.

10th Aug 2014 13:32 UTCRalph S Bottrill 🌟 Manager

I was just thinking the same thing, there is no indication of any analysis either.

10th Aug 2014 16:09 UTCTony Peterson Expert

The bulk composition of the rock and mineral assemblage are consistent with gehlenite. Here's an undoubted melilite specimen, with quite orthogonal-looking edges and corners:

http://www.mindat.org/photo-601836.html

Tony

10th Aug 2014 16:43 UTCErik Vercammen Expert

Tony,

You've made beautiful pictures of the melilite of the Löhley, and I agree they are of the gehlenite group. (BTW, I've collected tehere myself.) But the angles of the Chinese crystals seem not to be 90°, they look more like a (near-cube) rombohedron, like in this picture: http://www.mindat.org/photo-153540.html.

10th Aug 2014 17:05 UTCReiner Mielke Expert

Bulk composition? What is it in the bulk composition that would rule out something else?

10th Aug 2014 22:26 UTCRalph S Bottrill 🌟 Manager

We need some info on the geology and petrology, not just the bulk composition. Better still an XRD or probe analyses for such a rarely crystallised species.

10th Aug 2014 22:28 UTCTony Peterson Expert

OK, I'll look into it.

13th Aug 2014 13:18 UTCUwe Kolitsch Manager

I agree - not gehlenite, but either chabazite or dolomite.

24th Sep 2014 02:24 UTCTony Peterson Expert

Uwe, until I am able to establish the identity of this mineral, I suggest you delete, hide, or otherwise obscure this image.

Tony

24th Sep 2014 04:00 UTCAlfredo Petrov Manager

Thanks, Tony, I've temporarily moved them to your personal gallery.

Lovely stereo shot, by the way. Gorgeous.