Regarding the ID: It is based on the presence of Nb and REE in the qualitative EDS scan.(See the “Analysis tab” – the little bump next to Ce is Nd but wasn’t labeled). Such a scan is not sufficient for a definitive ID. For one thing, “ordinary” eudialyte can have REE. (However, "eudialyte" specimens with REE and Nd, if probed prior to 1998, might actaully be kentbrooksite - or another EGM.) I am supplying two labels. “Eudialyte group” is safe. “Kentbrooksite” is plausible. It is the most likely specific species. But, without WDS, which is prohibitively expensive, I can’t prove it. Sometimes even WDS isn’t enough. Such is the reality for eudialyte group minerals. Rarely will you find a specimen that has been microprobed. Almost never one that has been subject to SXRD.
The first pair of photos (FOV 6.4 x 4.3 mm) shows a well- formed kentbrooksite crystal ca 3.3 mm in maximum diameter.
The next pair of photos (FOV 6.7 x 4.6 mm) shows another good kentbrooksite crystal ca 4.5 mm with gray hexagonal nepheline crystals on the right.
The third pair of photos (FOV 4.7 x 6.6 mm) shows a 3.1 kentbrooksite crystal (perthaps partly altered) with brownish rinkite spanning ca 2.6 mm.
The seventh photo (FOV 4.4 x 6.8 mm) shows more kentbrooksite (3.1 mm) and rinkite.
The eighth photo (FOV 4.4 x 6.5 mm) shows yet another kentbrooksite crystal (ca 3.5 mm).
There are several other good kentbrooksite crystals. The one shown are probably the best. The ninth photo (FOV ca 3 x 4 cm) shows the main concentration of kentbrooksite.
But there is more – as shown in the full-view photo.
Ex Ron Waddell. The specimen has been sawn on two sides. There is a white crust on parts of the specimen that fluoresces blueish. Ron thought it might be hemimorphite, which is very unlikely. To me. it looks like natrolite with a crust of gonnardite. But it was not analyzed.
Single item shipping weight 13.7 oz (390 g). For shipments outside the USA, the quoted postage and shipping rate is good up to a total weight of 32 oz (950 g). If you have the patience to wait for a future auction, it may be advantageous to keep an “open box”. Let me know.
Weight is not so much of an issue for shipments within the USA. I will use “own box” Priority Mail. The quoted rate is good up to 16 oz. (But shipping additional items may require a larger, heavier, box). Above 16 oz the rate (good up to 32 oz) is $14.
