A lapidary (from the latin lapis, “stone”) is the name of a technique and a profession or hobby which consists of shaping and cutting stones, precious or fine, in such a way as to make them worthy of adorning jewelry, works of art, or objects suitable for lithotherapy (massages etc.)
The lapidary does not apply to the cutting of the diamond, which is reserved for the diamond cutter, because this cutting is specific due to the hardness of the diamond.