ONYX:   Onyx - a compact sedimentary rock is a type of limestone that formed by evaporation of cold water containing dissolved calcium, leaving a translucent
variety of calcite, often in the form of stalagmites and stalactites inside caves.
Its natural color is translucent white. The other colors come from minute
concentrations of chemicals carried by water dripping into the cave.
Onyx is extremely dense but locking in bending strength. It is often used for
interior counters, wall claddings and flooring.