Diamond is the hardest natural mineral. It is also one of the most valuable gems. Diamond is a crystalline form of carbon C. The word diamond comes from the Greek "adámas", which means indestructible. Thanks to their properties, diamonds have always been entwined with myths. In ancient times, people believed in their magical power. The rulers even believed that diamonds helped give them power and invincibility. Today, they remain a symbol that reminds us of the precious and important moments of our lives - the engagement, birth, anniversary and love of our loved ones.

Rating of diamonds

Each diamond is unique and has specific properties that prove its value.

Nevertheless, we can evaluate any piece individually. To assess the quality of a diamond, we use a globally recognized standard known as 4C:

  • Color - barva
  • Clarity – čistota
  • Carat – váha v karátech
  • Cut – brus neboli tvar diamantu


Diamonds occur naturally in clear, yellow, red, blue, green, brown and black. However, only clear to yellowish diamonds are included in the basic evaluation. He divided the GIA (Gemological Institute of America) into 16 groups. Other color shades are called "fancy".


The purity of a diamond is determined using a magnifying glass (at 10x magnification) and the inclusion content. As with the color, the GIA has issued a scale to determine the purity of the diamond.

Evaluation of the purity of diamonds

The specifics of the diamond



  • It does not contain any external or internal impurities
  • Extremely rare diamond
  • Built most often as an investment

VVS 1, VVS 2

(Very Very Small)

  • Inclusions that are difficult to detect
  • A rare and valuable diamond
  • Used in jewelry and as an investment

VS 1, VS 2

(Very Small)

  • Very small inclusions
  • Standard diamond of higher quality
  • Used mainly for the production of jewelry

SI 1, SI 2

(Small Inclusions)

  • Small, easily detectable inclusions
  • Standard diamond
  • Used mainly in jewelry

P1/I1, P2/I2, P3/I3

(Included 1-3)

  • Large and numerous inclusions easily visible to the naked eye
  • Used to make less luxurious jewelry

Carat weight

The weight of a diamond is measured in carats and is denoted CT. The weight is recorded up to three decimal places, with 1 carat being 0.2 grams. The more carats a diamond has, the more its uniqueness grows.


Another criterion for evaluating diamonds is the shape and quality of the cut. We divide the grinder into several shapes, of which we can highlight the 7 most popular.

A diamond cut with a round brilliant cut is called a brilliant. The shape of the diamond is precisely determined in order to guide and reflect light as best as possible. We call a diamond cut with a diamond with 57 (resp. 58) facets. Facets are individual sides of a diamond.

Diamond structure - parameters


Diameter - the width of the diamond from one side of the belt to the other  
Table - a large facet (area) on top of the diamond
Rundista - the edge of the diamond between the crown and the pavilion 
Crown - the upper part of the diamond from the belt to the table
- a small facet at the lower end of a diamond
Pavilion - part of the diamond from the rundist down to the bottom plate
Depth - the dimension of the diamond from the table to the bottom surface

Diamonds according to the quality of the cut

Grinding quality



They reflect almost all the light that falls on the diamond. (3% of world production).

Very good

They represent about 15% of the highest quality cut diamonds. They reflect almost the same volume of light as Excellent diamonds and are almost indistinguishable from the layman's eye.


They reflect most of the light.


They are still high-quality cut diamonds, but they are less shiny than diamonds of higher categories.


Most of the light that hits the diamond is lost, causing the stone to lose its luster.