Diamond rating: Discover the value and the carat of your stones

Assess your diamonds at retail & Diamonds Carats without any obligation. Below we provide some guidelines in order to understand on what we base our estimation. To determine the value of a diamond there are four parameters, developed by the American Gemological (GIA), in order to make accurate, objective and shared assessments. These four factors are also called the “4C” referring to the initials of the names: Carat, Colour, Clarity, Cut.

All these values ​​combined contribute to the determination of the diamond’s price.

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> Click on the table to see it in full screen.tabella diamanti 4c

1. Carat (weight)

The metric carat (ct) is the unit of mass used for diamonds. A carat corresponds to 1/5 of a gram (0.200 gr). A carat is divided into 100 points in order to be able to perform measurements on small stones (eg 0,20ct = 20 points)

In order to get a rough idea of ​​the size, in the table the relation carat and diameter in millimeters can be analysed. From 4.1 mm diameter of 25 points (0.25 ct) up to 11.2 mm to 5 ct.

stima diamanti

2. Colour

It is possible to evaluate the different gradations of colour by which a diamond is identified and the corresponding abbreviations in letters in the table. The less a diamond is coloured, therefore without appreciable tonal shades, the higher its evaluation will be.

3. Clarity (purity)

The purity of a diamond is determined depending on the number of inclusions and their visibility, their characteristics, size and positioning within the gemstone. The purer a diamond is (absence of inclusions), the higher its value will be.

  • IF (Internally Flawless): Neither defects nor inclusions are visible with a 10x lens.
  • VVS1, VVS2 (veryvery Small inclusions): very small inclusions, hardly identifiable with a 10x lens.
  • VS1, VS2 (Very Small inclusions): Reduced Inclusions are difficult to identify with a 10x lens.
  • SI1, SI2, SI3 (Small Inclusions): Small inclusions, easily identifiable with a 10x lens.
  • I1, I2, I3 (Imperfect): clear inclusions visible to the naked eye.

carati diamanti

4. Cut

The cut is the element that most emphasizes the beauty of a diamond and maximizes its quality; It’s the factor which determines the best all levels of brilliance and splendor. The perfect symmetry of the engravings and the polishing complete the unique style of each gem and its ability to optimally reflect the light by which it is surrounded.