Byssolite      Keystone Traprock Quarry, Cornog, Chester County, PA.  Ex Dr. Steve Chamberlain collection, circ. 1964.  This is one of those really special pieces of interest to any east-coast collector, collector of Chester County minerals or those looking for the truly unusual specimen.  It is an elongated ball of pure byssolite fibers that measures 8 x 4.1 x 4 cm.  Although compact looking it is probably just as it came out of the ground.  The crystals are complete and not crushed looking.  It probably only weights a couple of grams so it shocking to hold as it feels like a cotton ball in your hand!  I have not seen one of this quality outside a museum.  This is a very unique specimen and a mineralogical curiosity sure to raise lots of questions when viewed and handled.   $550