This is a ridiculously large euchroite crystal that perhaps is the largest American example of the species, according to some who I have shown it to. I have not heard of or seen any larger ones. It was collected by Bart Cannon, a well known collector of NE US minerals, in the 1970s and traded out of his collection sometime after. It is a unique, deep, vivid blue color that is hard to describe, but not similar to the euchroite from Europe in color or crystal form, by ay stretch. The piece is repaired in the middle and the photos show it at its worst, head-on right at the line of repair, to be honest about it. However when you look at it on a shelf, from an angle up or down, you do not see this crack as much. Now, it COULD be made into a truly incredible thumbnail specimen simply by undoing the repair. The result would be an arrowhead-shaped thumbnail crystal of 2 cm tall, 2 cm wide, and 4 mm thickness. The luster, and color, and habit, all make it leap out. It would be a world class thumbnail (without the repair) and in any case is a major US specimen in either size category. If it doesn't sell, I think I will have to donate to the Smithsonian as its the kind of rock that belongs there.