Professor WL Roberts, THE noted authority on phosphates of the amazingly rich and varied deposits in Custer County, sold this to John White at Seattle Show in 1971. On the back of White's label, he notes that " Prof. Roberts says that this is one of the three best known specimens of Leucophosphite." The large, sharp brown crystals are robust and stereotypic for the species, and are not the typical micros! Whether that holds true still today, I am ot 100% sure about. However, surfing the image gallery on MINDAT shows that most exmaples are micros, or clusters of micros to 7mm. These SHARP, euhedral, obvious and eye-visible crystals individually reahc 3 mm or so. They sit perched in a very interesting matrix of finely reticulated heureaulite crystals which cross the protected cavity in this rock, in which the leucophosphite has grown.