POL106JR Polyhedroid Agate Specimen

This is a polished specimen featuring blue-gray and black agate with stripes of quartz between, and a small opening in the center that has hints of golden yellow. The very back edge of the nodule shows the agate and quartz rough. 17.4 cm x 3.8 cm x 6.9 cm 1 lb 2.1 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. To view photos at a larger size, right click the image and select "open link in new tab."