Stone sculpture stone carving. Alabaster and softer kinds of serpentine, all about 3 on the Mohs scale, are more durable than soapstone. Alabaster, in particular, has long been cherished for its translucence. Limestone and sandstone, at about 4 on the Mohs scale, are the only sedimentary stones commonly carved. Limestone comes in a popular oolitic variety, about twice as hard as alabaster, that is excellent for carving. The harder serpentines can also reach 4 on the Mohs scale. Marble, travertine, and onyx are at about 6 on the Mohs scale. Marble has been the preferred stone for sculptors in the European tradition
Fencepost limestone formation so extensively for fencing." The source of this tough chalky limestone is the widespread and persistent topmost bed of the Greenhorn Limestone. The Fencepost limestone is the exceptionally wide ranging marker of the conformal contact between the Pfeifer Shale, which is the uppermost member Greenhorn Limestone below, and the Fairport Chalk, the lowest member of the Carlile Shale formation above. This stone was first scientifically mentioned as the "Fencepost limestone" by F. W. Cragin in 1896 when he originally attempted to name it Downs limestone. The Fencepost bed has also been called Benton limestone for its prominence as a