Alcatraz Penitentiary - SOLD 2.55" Showcase Concrete big10-2024 We've used this material to

We've used this material to make some of our bismuth crystals and it is a fun challenge

300 miles (6

and frankly they are best displayed in the open

which housed inside a glass-topped Riker display box measuring 4x3x1 (inches)

we've opted to include an 18" (45cm)

Alcatraz Penitentiary - SOLD 2.55" Showcase Concrete big10-2024 We've used this material toThis is an authentic piece of concrete from Alcatraz Penitentiary. Yes, an actual piece of The Rock!" This particular specimen measures 2. 55" 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.