The number of facets is not a measurement that equates to mms.
The best way to measure smoothness in a loose diamond would be to rub every external facet of the stone over fine silk. If there are any chips on the surface of the stone, it will snag the silk. This is not a common test of a diamond, though.
The five main components of a diamond's cut are the following:Table: This is the largest facet of a diamond which comprises the flat surface on the top of the stone, resembling a 'table'.Crown: This is the top portion and is located above the girdle and extending below the table.Girdle: This is the outermost edge of a diamond where the crown and the pavilion meet.Pavilion: This bridges the girdle and the culet and is located at the lower part of the diamond.Culet: This is the smallest facet of a diamond and is located at the very bottom of the stone.
A 6mm stone would be a.75 carat diamond.
Zero carats means that there is no weight to the stone. Perhaps that the stone is not a diamond? There is no notation for a diamond equal to zero carats.
The diamond is the hardest mineral and stone on earth: nothing natural can 'break' it. Diamond cutters use other diamonds to cut, facet and polish diamonds. Recently, however, powerful lasers have been added to the diamond-cutters toolbox.
Depending on which surface you want to name, perhaps the table -- the top of the cut stone, or a facet. There are many names for the facets. Learn more, below.
The cut itself is not an indicator of gem-stone price. The excellence of the cut may affect the price. The cut of a diamond stone is determined by the diamond cutter in order to preserve the other best qualities of the raw stone, such as colour, clarity or carat weight.
In terms of a round brilliant diamond, a properly cut stone should measure approximately 5.2 mm in diameter.
At the girdle, this stone would measure about 6.5 mm.
If the diamond is a round cut, a stone weighing a little over 3 carats would have the 9.5mm measurement at the girdle.
The plan for any diamond cut -- regardless of the style -- is particular to an individual stone and cannot be used on another diamond. Why? Because the plan for a diamond cut highlights a stone's clarity and colour, while preserving its maximum carat weight. You can read more about radiant cut, among all cuts, in the geometrical shapes tutorial, below.
If the stone is a round diamond, the stone measures about 10.6mm at the girdle. Remember carat is an indicator of weight, and millimeters is an indicator of length: the two are only loosely related in this case.