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Explore the secrets of diamonds

If you think of gold jewelry, the first image you have in mind is certainly that of a jewel set with diamonds and full of sparkle. Of all gems, diamonds are the most prized and precious. If diamonds are so famous today, it's because of their history, but also because of their properties.

The origin of diamonds

The first diamonds were found in India over 3,000 years ago, near rivers in the Golconde region. It remained the diamond mecca for centuries. Until 1725, India and Indonesia were the only places where diamonds were mined. The discovery of America also led to the discovery of large diamond deposits in Brazil.

The word diamond comes from the ancient Greek "adámas", meaning "indomitable". The hardest material in the world, diamonds have always been a complex material for lapidaries to master. Diamonds are highly prized by jewellers. They are made of crystallized carbon, and contrary to what you might think, they come in a wide range of colors.

Diamond grading

Diamonds are classified according to several characteristics. In the trade, we call these the 4Cs of diamonds. These 4 criteria determine the rarity and price of a diamond.

C for "Cut

Cutting a diamond is one of the most important things you can do. It's how the diamond reveals its brilliance, and disperses the rainbow spectrum of light. Because of its great hardness, a diamond must be cut and polished exclusively by another diamond. The main diamond-cutting centers are currently located in Antwerp, Belgium, and Tel-Aviv, Israel. The most common cut is the "brilliant" cut, which brings out the diamond's natural brilliance to the full.

C for "Color

Diamond color is a very important characteristic for many jewelry customers. Diamonds are graded on a scale from D to Z, with D being the best quality with a very pure white color, and Z being the worst quality with a very pronounced color. This grading is only valid for white diamonds. Other diamonds known as black are graded differently.

C for Clarity

Diamonds, like most other gems, contain inclusions. An inclusion is an impurity, usually appearing as dots or spots rarely visible to the naked eye. Diamonds are therefore also graded according to the visibility and number of these inclusions:

  • IF / FL: Absence of internal and surface inclusions at 10x magnification
  • VVS1 / VVS2: Tiny inclusion(s) very difficult to see with a magnifying glass at 10x magnification
  • VS1 / VS2: Very small inclusion(s) difficult to see with a magnifying glass at 10x magnification
  • SI1 / SI2 / SI3: Small inclusion(s) easily visible with a magnifying glass at 10x magnification
  • I1 / I2 / I3: Large and/or numerous inclusions visible to the naked eye

C for "Carat

Caratage refers to the weight of a diamond, and is probably the best-known criterion. 1 carat is equivalent to 0.20 grams. The name carat comes from the name of the seed of the "kuara" tree. This seed has the particularity of always having the same weight. It was therefore widely used in the gold and diamond trade. It is also the criterion that most influences the price: the value of a diamond is exponential according to its caratage. A 2-carat diamond will not be twice as expensive as a 1-carat diamond, but even more so, since they are rarer and the loss during cutting is higher.


At Thea Jewelry, we use HSI quality stones for all our diamond-set creations. This quality offers a perfect balance between color, purity and cut. HSI diamonds are diamonds with a slight tinge of color, inclusions visible under magnification (x10), but which are well cut to maximize their brilliance. These diamonds offer excellent value for money, as they look good without the higher price tag of tintless, inclusion-free diamonds.


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