NBC reported today that the source of the smaller bluestone rocks at Stonehenge, England, has been discovered. For years the existence of the fascinating rocks have spurred speculation as to how the rocks, some over thirty feet tall and weighing 25 tons got to their present location. Scientist have determined the “smaller” Stonehenge rocks–some more than thirteen feet tall and up to four tons in weight–came from the Carn Goedog area, about 140 miles from Stonehenge.
This is important, geologist Richard Bevins is quoted as saying, because “the work locates the exact sources of the 
stones, which highlight areas where archaeologists can search for evidence of the human working of the stones,” which could disprove the theory that the rocks were deposited during the Ice Age.
I was excited when I first read this article. My 9th GGF’, and the hero of my novel, Barnabas Horton, has a slab of engraved blue slate that covers his grave. He is buried in Southold, Long Island, but is said to have brought the slate with him from England. I had to wonder if perchance it was the same stone found at Stonehenge. It didn’t take me long to learn there is a difference between blue slate and bluestone.
Though the process is similar to produce the two stones, the composition is different. Bluestone is a sandstone that is the result of ocean sediments that settle after the body of water has disappeared. Compacted over a period of
Colorized Blue Slate
time, it results in a strong, layered stone.
Blue slate is formed when hardened clay–or mica–is compacted, forcing the water out of the clay. When compacted further and subjected to high heat, it forms shale and finally, a very durable blue slate. There are quarries near Mowsley, England, where Barnabas was born, filled with blue slate. He died in 1680, and the blue slate that covers his grave still exists and is legible, having been re-lettered in the 1800’s.
Let the words of my mouth, and the meditations of mine heart be acceptable in thy sight, O Lord my strength and my redeemer. Psalm 19:14, Geneva Bible 1599.