The investment diamonds must have the greatest overall weight, cut, colour, clarity and transparency:
referring to the diamond grading scale, those are only the D-color diamonds, IF and only VVSI1 and clarity Excellent cut and Very Good.
Another key feature is the absence of fluorescence.
As for the weight, is considered a range that goes from half carat to Carat and a half, according to that stated in the quotes made public.
Then, Diamond Private Investment S.p.A. offers the highest quality in its diamonds, making them the tiny minority of global production (approximately 0.4%).
Colour: colour analysis using equipment which are capable of breaking down the iris up to 12.000 tones and to distinguish, measure and to determine the relationship of prevalence between 7 colors that compose it.
Within those shades you find a classification scale that identifies the color to white or colorless to yellow. The gradations that detect the colour of a diamond, are indicated with letters from D to Z.
Clarity: conventionally a diamond is defined pure when there are no impurities inside up to 10 gemolite enlargements, by stating the sophisticated microscope used for recognized international certifications.
A diamond that corresponds to these characteristics it is classified as IF (Internally Flawless).
Cut: geometric shapes, angles, the size of the cut determine how refraction of light by the diamond and consequently its beauty, brilliance and obviously its value.
Cutting analysis uses sophisticated equipment that once again experiencing recesses, facets and are able to identify any faults.
Carat: the carat is the unit of measure by which the weight of the diamond, and corresponds to 0.20 grams. Also in this case the size of the diamond from investment must take account of its "saleable condition" in market conditions.
You should assume that the increase of the weight of the diamond is accompanied by an exponential increase in price, and not price linear.
To these parameters you can add a fifth, often overlooked and a source of misunderstanding:
fluorescence; the index of the fluorescence is inversely proportional to the value of the diamond, the more the diamond is fluorescent, the less valuable it will be.