Alcatraz Penitentiary - 2.604" Showcase Concrete bags form through a process of

form through a process of accretion in which small bodies collide and coalesce into increasingly larger forms

Showcase Specimens - Priced and sold individually

was recovered in Northwest Africa in the year 2000

88" polished Phylloceras fossil from Madagascar

Alcatraz Penitentiary - 2.604" Showcase Concrete bags form through a process ofThis is an authentic piece of concrete from Alcatraz Penitentiary. Yes, an actual piece of The Rock!" This particular specimen measures 2. 604" along the widest point. This specimen, from the famous Alcatraz Island, saw some 1,500 prisoners pass by it during the prison's operation. A certificate of authenticity is included.