Below the girdle or setting edge, which is usually not polished, is the base; this contains 24 facets, but 25 if a culet is present. The culet, or collet, is a very small facet at the base of the stone, but in modern cut stones, this is usually absent. The base thus terminates in a sharp point, but older cut stones always have a culet. Its absence eliminates the impression of a black spot at the bottom of the stone. Since the culet is generally protected when the stone is mounted in jewelry, its presence is now considered to be a disadvantage.

There are 8 five-sided facets, 4 of which are called pavilion facets and the others quoins. If no culet is present, these facets will be four-sided. The other 16 split facets are triangular in shape, and consist of 8 cross facets and 8 skill facets (also called bottom half or break facets). All these facets may be described by different names, according to the place of cutting.
The angles between the normals of facets should be 45 °. Between the table and templets, they should be about 40 °, between the culet and pavilion about 40°, between the cross facets and the table about 45 °, between the cross facets in the base and the culet about 45 °, and between the star facets and the table about 26°. Totally reflected light should come through the side facets of the crown, and not through the table. These proportions are very important in order to give the maximum brilliancy from the diamond. A well cut stone must have these definite proportions between its width and height, and the facets must be inclined at these angles. Actually, most London lapidaries make the angle between the bezel facets and the girdle 35 °, and the angle between the girdle and the pavilion facets 42 °.

Turquoise is also deepened in color by artificial means, aniline dyes being sometimes used. But the coloring matter soon fades, this type of dye being most unstable. Quartz cat’s-eye is also stained a dark blue and also pink, both unnatural colors to this stone. We have already noted that heat applied to smoky quartz, amethyst, zircon, topaz, and other stones affect their color, and that iris quartz is obtained by a dye being introduced into artificially created cracks within the material. Coral and mother-of-pearl are both stained to improve their color, aniline dyes being used. Some new coral is covered with a varnish after being colored, but this wears off in course of time.
Much of the so-called “antique” amber, and “Chinese” amber is the result of staining new material to simulate the dark brown and clear red varieties, which are much liked. The rough is immersed in oil to which coloring matter has been added, and then gently heated for some days. After being dried,  cleaned, and polished, the amber will be found to have absorbed the coloring matter, although often only superficially. Amber is very brittle, so unless the heating is carried out very gradually, the material will split or crack. The colors obtained are often very similar to the natural shades, but they are seldom permanent. Such amber is sold at an enhanced price.

A green color is sometimes seen in the clear or semiclear amber, while compressed amber, which approximates to a reconstructed amber, may be stained to any color. A green very much like that of Chinese jade is sometimes seen, but as amber is softer and lighter than any stone, there is no difficulty in distinguishing it.

The chief forms of cutting used are the brilliant cut, the step (or trap) cut, the mixed cut, the rose cut, and various forms of cabochon cuttings. Transparent stones are usually faceted; opaque and translucent stones are generally cut en cabochon. There are a number of other so-called “fancy” cuts, these being usually seen with diamonds, topaz, amethysts, aquamarines, and a few other stones.
The brilliant cut is so called because it is characteristic of the diamond. The number of the facets, their inclination to each other, and the ratio of the width to the depth of the stone are factors which have been definitely established by practice and calculation, and any departure from the acknowledged standards will lessen the brilliant effect which is such an outstanding property of this gem. If properly cut, there will be 57 facets (or 58 if a culet is present), and the brilliancy of the finished stone will depend largely upon the proportion of these facets to each other.
The girdle divides the upper part, or the crown, from the base, and it is usually circular. It is the only part of the finished stone which is generally left unpolished. If the girdle is not circular, the arrangement of the facets will be distorted. It should be as
thin as is practical but not so thin that there would be a risk of chipping when the stone is set in a mount. In order to obtain the maximum brilliancy and fire, light falling on the table (which is the broad, flat, large facet on the top of the stone) should be refracted and then reflected from the base facets, ultimately emerging from the crown facets. Additional facets are sometimes used in large stones, and their inclination might be modified to suit the optical characteristics of the particular specimen.

Of the 57 facets, 33 are contained in the crown. There is the large facet on the top surface, called the table, which is octagon shaped; 8 triangular star facets, 8 quadrilateral facets (4 templets and 4 quoins, sometimes called bezel and top main facets, or top corner facets), and 16 triangular facets (8 cross and 8 skill facets, sometimes called top half or break facets).

The special shaping and hollowing of bowls, ash trays, ink wells, and similar articles is carried out in much the same way, the stone being pressed against smaller caborundum laps. Polishing is effected by laps which are covered with tripoli powder and oil. This work is also laborious; a certain amount of heat is generated by the friction, and care must be taken not to develop or enlarge cracks within the material.

Drilling is specialized work, and requires much experience and a delicate touch. The drill is set with two specially shaped pieces of black diamond, and considerable skill is necessary to set these correctly so that they are not broken in working. The driller sets his own diamonds, their position varying according to the size of hole required. If the prevailing fashion is for beads or button earrings, the driller has a busy time. A bad driller will break his drill frequently and thus make his work unprofitable. The correct setting of the drill is therefore of the utmost importance.
Two black diamonds, which are very small in size, are selected, and these must be shaped if necessary so that they are triangular and of the same length. Constant examination with a loupe is required before they are considered satisfactory. They are then inserted in a wooden holder which is topped by a piece of lead, the lead being grooved to take the stones. They are hammered in and then tested on glass, and lead above the surface of the diamonds being filed away. Their positions in the holder are such that, when the drill is rotated, the diamonds will cut a very small circle. This circle will be deepened by the rotation of a bow until the material is bored through, the narrow core being thrown out as a powder. Although white diamond is harder than the black, it is not so tough. Fine drills are always set with two small black diamonds; larger drills may have more than two pieces inserted.