Buying diamonds: 10 terms to know and understand

  • Learn more about the different components of a diamond and their impact on its quality.
  • Processing techniques, for example polishing, also influence the diamond’s effect.


What is the girdle of a diamond? What is the crown? And what exactly is meant by the symmetry of a diamond? Below, we will shed light on some frequently used terminology regarding diamonds.


1. Carat

The carat is the unit used to indicate the weight of a diamond. 1 carat equals 0.2 grams (approximately the weight of a paperclip). The weight of a diamond can also be denoted in points.

2. Crown

The crown is the upper part of the diamond that sticks out above the girdle and pavilion. The crown has the largest diameter of all the diamond’s components.

3. Culet

The culet is a tiny facet at the bottom most point of the diamond. It is preferably invisible to the naked eye. This is because if facet is too large a dark spot will be observable, as the light of the diamond will not be reflected.

4. Depth

The depth of a diamond is the distance between the bottom most culet and the topmost table. The depth influences the diamond’s cut and is indicated by a percentage.

5. Diameter

The diameter is the dimension of the diamond from one side of the girdle to the other side.

6. Girdle

The girdle is the widest part of the diamond. It is a small band that separates the crown from the pavilion.

7. Pavilion

The pavilion is the lower part of the diamond. It encompasses the area between the girdle and the culet. The pavilion is a synonym for the base of the diamond.

8. Table

The table is the large topmost flat facet of the diamond. Because the table is both wide and flat, it reflects the most light, giving the diamond its ‘fire’.

9. Symmetry

The symmetry of a diamond is graded from Excellent, to Very Good, Good and Fair.  How it is graded depends on the diamond’s proportions. A diamond is meant to observe certain dimensions; otherwise this has a negative impact on the brilliance of the diamond. The symmetry of its cut is stated on the diamond’s certificate.

10. Polish (diamond finish)

The diamond’s finish determines its brilliance and how the light is reflected. By polishing a diamond, the lines from the different facets become more visible. A diamond that is well polished will reflect and diffuse the entering light better than a poor polished diamond.  Just as with symmetry, the diamond’s polish is graded from Excellent (a perfect finish with unobservable facet lines), to Very Good (the lines are extremely difficult to make out), Good (the lines are difficult to make out when magnified) and Fair (the lines are discernable when magnified).

 BAUNAT DIAMONDS advises its possible investors regarding a suitable investment diamond.

Read the following for more information regarding the purchasing of diamonds:

-       Purchasing diamonds as alternative investment.

-       Buying diamonds or investing in mixed investment funds

-       Four steps to take when buying diamonds online