The hardest mineral found in nature, resistant to all acids and alkalis and also from other types of carbon. It is not for nothing that the origin of the name of the stone is associated with the Greek word adamas – “invincible.” However, it can be affected by oxygen and fluorine at temperatures between 600 and 800 degrees Celsius. At 3700 – 4000 degrees Celsius, the diamond can be melted. In addition, diamonds are not made up of carbon alone – they can contain silicon, iron, titanium, magnesium, calcium oxides, nitrogen and other impurities.
Diamonds are found in craters ranging from 10 to 1300 m. wide, which are filled with fragile rocks. Most mines are located in Canada, Russia, Africa and Australia. Diamonds form at a depth of about 100 – 200 km. where the surrounding temperature reaches 1000 – 1100 degrees Celsius and enormous pressure is created. After spending billions of years in the depths, diamonds are blown to the surface during volcanic explosions, lifted by magma.
The diamond is normally clear, but not necessarily colorless. In terms of price (from cheapest to most expensive), diamonds are ranked as follows: yellow, brown, champagne, green, pink, blue, and finally rich red. According to color, diamonds are graded using letters of the alphabet from D (completely colorless) to Z (visible colors).
Stones are weighed in carats (ct.) One carat = 200 milligrams. The heavier the stone, the more expensive it is. To be considered investment diamonds, the stones start at 1 ct. and their color corresponds to the D – G tier color gradation (the most white), good cutting, with recognized laboratory certificates. The stones are evaluated by gemologists. (Gemology is the science of stones).
The prices of investment diamonds start from 5000 – 6000 Eur. World-renowned laboratories: GIA (American Institute of Gemology), HRD, IGI – not only issue certificates, but also engrave (inscribe) diamonds with a laser. The certificate must indicate not only the characteristics of the diamond, but also the date and the certificate number.
When an investment diamond is incorporated into a piece of jewelry, it performs a dual function – it adorns and preserves its value. Colored diamonds (fancy) are considered an investment from 0.25 ct. weight because they are rarer – especially pink and blue. There are units of red diamonds in the world. According to the 4C Diamond Rating System: Not only weight and color are important when choosing diamonds.
Worldwide, diamonds are valued according to the “4 C” methodology:
- carat weight
The U.S. Institute of Gemology (GIA) developed such a methodology in 1939. It is generally said that the more faceted a diamond is, the stronger it will shine. The level of ribbing can range from ideal to bad. A cut diamond is called a brilliant.
Diamond polish rating chart:
Color rating chart:
Detailed explanation of the GIA scale:
The value of a brilliant or diamond can be checked in the Rapaport table, which is updated and published weekly. The world’s main diamond providers (mines): De Beers, Rio Tinto, AlRosa. It is said that global diamond mines are starting to dry up and due to that as early as 2050 there will be a diamond deficit in the market.