The Girlfriend's Guide to Jewellery
17: Faceting 2011-06-01
Typically, transparent gem quality material is polished and facetted. Faceting should leave the stone symmetrical, evenly proportioned and with good polish or finish. Revealing the beauty of the gem material is the goal of the cutter, that and maintaining maximum weight from the original rough material. Some material is still cut by hand. Exceptional gem material is cut by a master-hand.
There are various patterns of faceting and most facetted gemstones have a crown, a girdle and a pavilion.
The ‘girdle’ separates the ‘crown’ from the ‘pavilion’ and can have the appearance of a fine to thick ‘whitish’ line. Often the ‘girdle’ is left unpolished though it is becoming a style to facet the girdle of diamonds. While the girdle is the smallest part of a facetted gem it plays two important roles. One, it defines the outline of the stone’s shape: an irregular girdle will give a stone an irregular and uneven shape; and two, it is around or on the girdle that the setting will rest to secure the stone in the mount.
The ‘crown’ is the body of the stone above the girdle. Some stones are facetted with a checkerboard pattern all over the crown. Otherwise, the large flat facet on the top of the stone is called the ‘table’. The table is surrounded by smaller ‘crown’ and ‘star’ facets, which slope away from it. The design and placement of these facets are designed to work in concert with those on the pavilion of the stone.
The ‘pavilion’ is the body of the stone below the girdle. It is usually the largest volume of a facetted gemstone and it is usually fully facetted. The placement and number of facets are designed to give a transparent stone sparkle and can often help to intensify its face up colour. The design and placement of these facets are designed to work in concert with those on the crown of the stone.
The one exception to this three part arrangement is the rose cut. It is an archaic form that basically is a heavily facetted crown-shape with no large table facet and no pavilion. The faceting on a rose cut is usually done by hand and is arranged in an informal pattern. The underside of a rose cut is a single, flat, polished surface.
There are almost as many patterns of faceting as there are gemstone cutters. Brilliant and step cut are the two most commonly used. Coloured gemstones are often cut in a modified or combination of facet patterns. The faceting can be adjusted to many shapes and sizes of stones for maximum beauty and weight retention.
Diamonds are the notable exception to these modifications. The faceting of diamonds is consistent and precise. Of the four ‘C’s’ of diamond grading, cut is the number one ‘C’. It is of primary importance in releasing the beauty of diamonds.