Hingganite-(Y) (rare) - Zagi Mountain, Pakistan

An ultra rare double terminated crystal of Hingganite, with inclusions of Riebeckite, from new finds at Zagi Mountain, Peshawar, North-West Frontier Prov, Pakistan. Preliminary XRF analysis yielded an approx composition of Ce2Be2(SiO4)2(OH)2 [which most closely matches Hingganite-(Ce)]. I then had the sample analyzed by Raman spectroscopy, but was informed by a Russian researcher that only Microprobe analysis can confirm which analog this is. The researcher mentioned that all Hingganite he had tested from here turned out to be Hinggainite-(Y), and contained Rare Earth Elements in the following relative quantities Y>Nd>Ca>Ce>Sm>Pr.   

This specimen has color change properties, but not under the same light conditions needed for the color change seen with Alexandrite.  Most of the time this specimen appears a brownish yellow (under daylight, led, incandescent, and fluorescent). However with Mercury vapor bulb illumination (which contains high uva and uvb output) the crystal appears a dramatic bluish green. The specimen is not fluorescent under SW or LW UV light, and was only mildly pleochroic in a polarized light test. I've recently learned that this color change is due to the presence of the REE ion Nd3+.