Large chunk of basalt with the top coated with translucent calcite crystals which are in turn covered with dark pastel green botryoidal prehnite from the Upper New Street Quarry in Patterson, Passaic County, New Jersey. Measures 5 x 5 x 4 inches (13 x 13 x 10 cm). Excellent condition. Weighs 3 pounds. The color did not come out in the photos. The prehnite is much darker green than the pictures indicate.