Judging Diamonds

Judging the Crown

High crown diamonds have reduced brilliance. In addition, the upper girdle and bezel facets will appear crinkled. Also, there may be eight flower-like patterns visible near the corners of the table.

Judging the Table

If the table size for your diamond is too large, the diamond won't have much sparkle or fire (i.e., flashes of rainbow colors) and it will have a thin crown. If the table size is too small, the diamond won't display much brilliance, it will appear small for its weight, and a high crown.

Judging the Girdle

Avoid buying diamonds that have a girdle exhibiting the following characteristics:

  • A girdle that is too thick or too thin
  • A girdle that is very uneven in thickness
  • A girdle that is wavy or slanted
  • A girdle that is rough or bearded (i.e., contains tiny hair-like fractures)

If the girdle is too thick, the diamond will lack brilliance, look smaller than its actual weight, and will be difficult to set. Diamonds with thin girdles are harder to set and can chip easily. Bearded girdles can also lower the clarity grade of diamonds. Plus, a diamond having a bearded girdle can trap dirt easily, appear gray and have a dark look.

Three types of girdles:

  • Faceted (i.e., it appears to have facets going all the way around the girdle)
  • Bruted (i.e., it appears frosty or waxy)
  • Polished (i.e., with no facets and has a clear continuous rim of glass going around the diamond)

Judging the Profile

It's important to judge a diamond from the side. Characteristics that you should look for:

  • Thickness of the crown
  • The depth of the pavilion
  • Thickness of the girdle
  • Size of the diamond (bulky or flat)