It can be very hard to distinguish gmelinite from chabazite at MSH - even with EDS. These small (ca 1.3 mm) “fuzz balls”, where initially thought to be chabazite due to similarity with known (analyzed) chabazite specimens found many years ago by the Horváths. But EDS (see the “Analysis” tab) pointed to gmelinite, and this has now been confirmed via PXRD. More (expensive) analysis would be required to absolutely prove that this is gmelinite-Na, but, time-after-time, all detailed analyses of “gmelinite” from MSH have shown gmelinite-Na.

FOV is 6.0 x 4.6 mm in the first pair of photos and 4.3 x 6.4 mm in the third photo. These are all just slightly different views. The fourth photo (FOV 3.5 x 2.3 mm) is a close-up (ca 30 X).

The matrix is largely microcline, but there are also some small (<= 0.6 mm) “saucers” of a donnayite group mineral. These are shown in the fifth photo (FOV 3.1 x 2.0 mm).

Almost every specimen from this find had similar "donnayite like" material, but of rather varying habits. Two other specimens, chosen to “look” as different as possible  were analyzed via qualitative EDS. Both had nearly identical scans. (One of these is reproduced under the “Analysis” tab.) There is a lot of Ba, which suggests ewaldite, but also Y, Ce and Sr which point to mckelveyite-(Y) or an intergrowth of mckelveyite-(Y) with donnayite-(Y). (The Fe and S may be coming from pyrite, which almost always associates.) Syntactic intergrowths of the “donnayite group” minerals with each other (and with synchysite-(Ce)) are almost the norm at MSH and make it very difficult to pin down the specific species – usually more than one. 

Single item shipping weight (small box with TN case) is 2.7 oz. Up to a total weight of 8 oz (225 g), this could be combined with other items from this or future auctions for the same postage. If you wish to keep an “open box”, let me know. Please see my "Shipping Policy" for details.