Georgian Limestone®. *KeyStone Exclusive* This Silurian Period Limestone was formed 443–417 million years ago and is the best overall value armour, wall, & steps on the market today. Great aesthetics, value and quality,  make this clearly our #1 selling stone. This uniform calcitic formation stone gives off a light grey colour with some mountain range buff undertones Sizing: Armour (=14, 24, 30” H-2x3’, 3x4’, 4x6’), - . Drywall (=2”,4”,5-8”, 8-10”)- H x 2-3 D x 3-5 L, 10-12” H x 2-3 D x 3-4 L (2x3 3x3). Steps 5-8” (2x3’,3x4’,4x6’),6-8”Hx 2-3Dx 3-6 L.