This is a large cluster of intergrown, splendent, brassy crystals, of pyrite, to 4.5 cm across. The back side is made up of sparkling, pyrite crystals averaging .5 cm across. Only at one end on the back side is the specimen contacted, and this is of no significance at all - it is absolutely complete everywhere else and remarkably pristine! This is one of the few pyrites from this locality I have ever seen, out of literally thousands, that has such completeness and condition combined with the top quality of luster and form. It is common material, absolutely, in a general sense...but a piece like this is NOT common quality and you could spend a decade looking for such. Francis, who has taste so persnickety in damage and aesthetics that he is almost impossible to sell to (I say this as a friend, as a compliment!), took this one as one of his few non-gemmy crystals and held it for many years. It is THAT good.