Gemstones can be cut into a number of shaped. Round brilliants are being the most common in the modern age, cabochon (a rounded dome) being the oldest style of polishing/cutting a gem. A lapidarist is one who cuts rough gems. Setting them into a jewellery is what a goldsmith does. Jason Bellchamber sets each stone at the workbench in our store in London ON. That being said, there are 3 dimensions or planes which must be considered to make sure the gemstone is straight when it is finally tightened into place. The top (xy), the profile (zy) and the side (zx) are the 3 sides or planes used. To simplify; A plane has 2 Dimensions (and is often considered 2D), a Point has no dimensions, only position, a Line is one-dimensional, a Plane is two dimensional (2D) and a Solid is three-dimensional (3D).
