Eudialyte is a fairly common mineral at MSH, but there is no way to distinguish it visually from other members of the eudialyte group also found there. Even specimens from a rigorously analyzed find are not necessarily the same species. For one thing, zoning is very common. In this particular case, the analyst felt that the species was most likely kentbrooksite because of the strong Mn peak and the presence of REE elements (Ce). (See the “Analysis” tab.) Given the chemistry of the other EGM minerals at MSH, that’s probably a reasonable interpretation. But I am not totally convinced. There is an oxidized coating which is probably the source not only of the Zn, but also of at least some of the Mn as well. Only a probe (plus perhaps XRD etc) could tell. That’s way too expensive to consider. Hence “Eudialyte group – possibly Kentbrooksite”.

The two pairs of photos are just different views of the “front” of the specimen. The largest crystal is about 7 mm. Both the large and small crystals are complete, but they do contact other (partial) crystals (and, of course, the matrix).

Single item shipping weight (with TN case) is 3.0 oz (84 g). For shipments outside the USA, up to a total weight < 8 oz (225g), this can be combined with items from this or other auctions for the same postage.

Within the USA, postage for total weights up to 13 oz, ranges from $4.50 to $6.50 (including packing etc) regardless of destination. Above 13 oz, I will use Priority Mail ($7.25 - $9.20 including packing – varies by destination).