Ideal Diamonds

Ideal Diamonds (Characteristics)
Yes, there are certain distinguishing characteristics that IDEAL cuts have.Firstly, on an 'ideal cut' if you look directly down and straight into the table of the diamond with a 10X loupe you will notice a certain phenomenon. Focus towards the bottom point of the diamond (the culet) and you should notice a small octagonal formation around the culet (point on the bottom of the diamond). This is a reflection that can be observed in diamonds that are not deeply cut. This image should extend about 1/5 to 1/3 of the table diameter. The size of this sort of circle, shows the pavilion depth of the stone.The larger this circle the deeper the stone is.
To achieve maximum brilliancy in a diamond it is essential that the facets be flat, planar surfaces. Hasty and careless polishing can leave wheel marks that affect brilliancy and luster. These wheelmarks are seldom visible to the unaided eye. The wheel marks cause the surface to be very minutely grooved, and in turn these minute grooves caused diffusion of the light that is transmitted through and reflected from the diamond. A well polished diamond will show no evidence of wheel marks under 10X. Wheel marks can easily reduce the brilliancy of a diamond to below its optimum beauty.
The machines that measure facet percentages and angle at his time only report one angle, but future technology is going to address facet yaw, and address the aspects of a three dimensional item
GIRDLE:
The foundation of the diamond is directly relevant to how well the girdle is created.
Preferably, the girdle should be faceted or polished, and the most uniform in thickness. Be aware that the variance of thickness affects the facets cut and polished near the girdle. If the girdle varies then the facets will vary. This really isn’t that noticeable to the eye, but if you really want super precision in the cut, it a consideration that shouldn’t be omitted.
The girdle of diamonds can range from extremely thin to extremely thick. This applies to both GIA and AGS graded diamonds. Avoid diamonds with extremely thin or thick girdles. Extremely thin girdles can be chipped easier than ones that are thicker, and very thick or extremely thick girdles can detract from the appearance of the diamond.
A well finished girdle surface is one that is so smooth that appears similar to the other facets, a glassy appearance.
If a diamond is rounded up too quickly in the fashioning process, the result will be a fuzzy appearing girdle that may be rough. A rough girdle may make a diamond appear greyer or darker when viewed face up. This would be caused by oil or dirt becoming embedded in the girdle surface.
”A girdle may be faceted or polished and this has no effect on the value of the diamond, unless it appears unattractive.
Careful and precise girdling also results is a “rounder” stone. Not the minimum diameter measurement and the maximum measurement on a GIA or AGS report. Find a diamond with the same minimum and maximum measurements of the diameteris uncommon as the equipment used is capable of producing a perfectly round girdle. Most diamonds have a small variance in the measurements, but there are some that are so far apart that the stone may appear out of round to the naked eye.
CULET:
The culet should appear as a tiny polished facet at the tip of the pavilion. Should the culet be chipped or abraded, this will detract from the diamond's appearance. If the culet is rough or unpolished, it will appear as a frosty white dot. In a finely cut diamond, the culet should be either pointed, very small, small or medium.
The culet should also be centered as much as possible. This is particularly important in fancy shaped stones, such as the Princess cut. Stones that have an off center culet generally have lopsided pavilions. This isn’t reported on most lab reports, but is on the advanced Sarin reports.
SYMMETRY:
Symmetry discrepancies should not be visible under 10X if a diamond is to be considered well cut. The table must conform to the ideal octagonal shape. The facets should all meet at a point and if they fail to do so they would be misshapen as a result. When a diamond is graded for symmetry, the following 8 features are taken into account.
1.) Table or culet slightly off centre.2.) Unequal sizes of opposing facets.3.) Misshapen facets.4.) Table not octagonal.5.) Girdle outline slightly out of round.6.) Table not parallel to girdle.7.) Facets fail to point up.8.) Pavilion and crown main facets out of alignment.