Here in Washington state, on the east side of the Cascade mountains, the land is covered in ancient lava flows.  As these lava flows cooled they began to contract, the contraction caused the newly formed stone to fracture vertically, resulting in the formation of hexagonal columnar basalt.  Basalt is a very common type of rock, however, the beautifully formed columns that we use are not so abundant.  Every column has a crust that has formed on the outer layer of stone which is caused by weathering, with colors ranging from tans and beige to reds and copper colors and in some cases gray and black.  Within the colorful crusts, the stone itself is a beautiful rich black color which can be polished to a brilliant black shine.  Basalt is a very dense, fine grained stone with a weight of 188 pounds per cubic foot which is about 10% heavier than granite.  These naturally formed basalt column stones can be absolutely visually stunning.