Diamonds Online: Buy Certified Diamonds

Each diamond is a unique natural product and is rarely completely ‘flawless’. Clarity is determined on the basis of the number, size, lightness and location of 'inclusions', as foreign bodies or flaws in the crystal are known. The smaller and fewer inclusions a diamond has, the higher its value and clarity. The official grading scale ranges from FL/IF (flawless) to P3 (obvious inclusions visible to the naked eye). Most inclusions are so small that they are only visible under 10-fold magnification and thus do not impair the beauty of the stone. RENÉSIM supplies diamonds in grades FL to SI2. In the categories FL to VVS2, inclusions are so small that they are invisible to the naked eye. In grades VS1 and VS2 inclusions are only visible under a microscope.

The culet is the smallest facet at the base of the diamond. Ideally this facet should not exist at all and the diamond should end in a perfect point. A large culet can impair the beauty of a diamond, as it appears as a black point when viewed from above.

All of our diamonds are supplied with a certificate from an independent gemological institute. The certificate is a printed document in English that guarantees the authenticity of the diamond. When issued by a reputable gemological institute (e.g. GIA, HRD, IGI or EGL), the certificate also contains a full description of the quality of the diamond. Please note that the interpretation of internationally valid diamond assessment criteria can vary from one gemological institute to another. While institutes such as GIA, IGI and HRD are known for their rigorous interpretation, in some cases diamonds certified by EGL are assessed as 1 to 2 grades higher than they would be by other institutes. You should take this into consideration when comparing diamond prices.

Although diamonds can be found in all colours, over 90% of them have yellow tints from virtually colourless to visible yellow. As a general principle, the more colourless ('white') a diamond is, the higher its value. Light passes easily through a colourless diamond and is reflected to best effect. Diamonds are classified using a scale ranging from D to Z, in which D stands for the best and most colourless (whitest) diamond. RENÉSIM only supplies diamonds in categories D to M. Our diamonds thus have only a very slight yellow tint or are completely colourless.

Cutting refers to the cutting and polishing process that gives shape to the diamond, intensifies its brilliance and brings out the visual effects inherent to the stone. The cut of a diamond is therefore the main criterion on which its value and beauty are judged. We recommend reserving a significant part of your budget for the best cut you can find, as the character of a diamond is primarily determined by its brilliance and fire. Therefore, the cut of a diamond is a central criterion by which its value and beauty is assessed.

The depth of a diamond gives the ratio between its height and diameter (height:width). Larger or smaller proportions impair the brilliance of the diamond by preventing the light from reflecting perfectly.

The dimensions given show the size of the diamond as length x width x depth (in millimetres).

Fluorescence is the term used for the visible glow emitted by some diamonds under ultra-violet (UV) rays. Around one-third of all diamonds are fluorescent to a greater or lesser extent. However, fluorescence only impairs the appearance of around 10% of these stones (shown in their certificate as Medium, Strong or Very Strong). Over 95% of fluorescent diamonds emit a blue glow under ultra-violet light; other colours such as yellow or white are very rare. Blue is the complementary colour to yellow, the tint most commonly found in diamonds. Diamonds with medium to strong fluorescence are therefore often preferred as they 'cancel out' the natural tint of the diamond and make it appear whiter. In the majority of cases the strength of fluorescence has little effect on the diamond's appearance. In rare cases highly fluorescent diamonds may have an oily or milky appearance; however, this applies to fewer than 0.2% of all fluorescent diamonds.

The girdle of a diamond is the circumference between the upper and lower part of the cut diamond, and thus its widest part. We do not advise choosing a Very Thin or Extremely Thin girdle as this increases the diamond's risk of chipping. A Very Thick or Extremely Thick girdle is also not recommended, as it concentrates a great deal of the diamond's weight in the middle, sometimes causing the stone to look smaller. The best girdle ratings are Thin, Medium, Thick or Slightly Thick, or a combination of these (e.g. Thin-Medium or Medium-Slightly Thick).

A diamond must be extremely finely polished to ensure no traces of the cutting process are visible on the surface and all corners and edges are crisply defined. Polishing traces are almost always invisible to the naked eye but may impair the brilliance of a diamond to a very slight extent. Polish is graded in categories from Poor, Fair, Good and Very Good to Excellent.

All prices include Value Added Tax and insured shipping.

The round brilliant-cut is considered the most classic diamond shape.

Brilliant: Classic round, faceted cut

RENÉSIM also offers diamonds with other exceptional cuts:

Princess: Square faceted diamond
Emerald: Stepped octahedron with straight facets
Asscher: Faceted square cut with truncated corners
Marquise: Faceted oval cut with ends tapering to points
Oval: Faceted diamond in oval shape
Radiant: Octagonal diamond with star facets
Pear: Pear-shaped or teardrop diamond, faceted
Heart: Faceted diamond cut in heart shape
Cushion: Diamond with rounded corners and large facets

Symmetry is the term used to describe the form of a diamond and the arrangement of its facets, which should be as uniform as possible. The quality of symmetry of a diamond impacts on its brilliance. The Symmetry is graded in categories from Poor, Fair, Good and Very Good to Excellent.

The table percentage of a diamond gives the ratio between the table (the central top facet) of the diamond and the total diameter (table:width). Ideal table proportions bring out the brilliance of a diamond to its best effect.

Carat describes the weight of a diamond. One carat weighs 0.2 of a gram. A one-carat brilliant has a diameter of 6.4 mm, while a two-carat brilliant is 8.1 mm in diameter. Although the two-carat diamond weighs twice as much as the one-carat stone, it does not look twice as large. The size of a diamond is not only determined by the number of carats, but also by the dimensions of the stone in millimetres, its proportions and the quality of the cut.

In 2010, RENÉSIM embarked on a revolutionary journey, with the mission to provide first class gemstones and exclusive fine jewellery collections online. In addition to delivering high quality products, we provide our customers with expert advice, finest designs and security with each and every purchase. Our complementary service is part of our core values at RENÉSIM.

RENÉSIM allows you to revoke your declaration of agreement for an extended period of 30 days upon receiving your pieces of jewellery. This service also applies to customized and engraved products. In all other cases, the general cancellation laws apply, which you can see here ..

Diamonds that have been used to finance illegal and militant activities have no place in our carefully selected product range. RENÉSIM only partners with diamond cutting and polishing centres, which process ethically sourced diamonds. We strive to go beyond the requirements of the Kimberly Process by categorically declining diamonds, which have been sourced from countries in which the Kimberley Process is not fully enforced. This applies to regions such as the Ivory Coast, Zimbabwe or Venezuela. We also offer loose Diamonds in the original sealed packaging (directly from the certificate institute) upon request.

We promise to provide our customers with an excellent product and service package at unbeatable prices. Should you come across better quotes, we will gladly review our offer and try our best to align our prices.

Our jewellery range delivers premier designs at the highest standards of quality. However, if you aren’t able to find what you're looking for, we will help you create personalised products that match your wishes – with no extra charge.