Shattuckite is a rare copper silicate and this beautiful, very large, partially polished nodule is from a find at Navojoa, Sinora, Mexico. The intense blue hues are striking and the scattered chrysocolla is a very nice accent. Outstanding, dense carving rough. Weighs 364 grams or just over 0.8 pound. Rare on the market from this locale. This is old material from an old collection which turned up in Tucson.