POL108JR Polyhedroid Agate Specimen

This is a polished specimen featuring gray and blue-gray agate with speckles of yellow. It has a few black ribbon bands and small black dendrites, and one large dendrite tree coming from the edge into the agate. 17.2 cm x 16 cm, between 27 mm - 4 mm thick 1 lb 2.8 oz Polyhedroid Agates were found in Paraiba, Brazil, but are now unavailable. They are pseudomorphic formation of agate, forming in the negative space between large crystals of calcite or aragonite. They uniquely feature naturally flat surfaces in a variety of angles.