First Criterion: Carat

The evaluation of gemstone weight utilizes the unit of Carat (ct). Every Carat can be subdivided into 100 points and equals 0.2 grams. An intriguing fact to keep in mind is that the size of a diamond does not directly correspond with the number of carats, as they simply denote its weight. The discovery of diamonds exceeding 1 carat is a rare event, driving up their price range. At BAUNAT, we offer diamond rings set with 0.30, 1.25 and even 3.00ct, each finely selected to represent our commitment to quality and smart investment.

Why the same carat looks different across gems (size vs weight)

Carat measures weight, not visible size, and density differs between gem species. The same millimetre diameter can therefore translate to different carat weights. Concrete examples for a round cut at similar diameters illustrate the effect:

• 6.5 mm round diamond ≈ 1.00 ct; diamond’s density makes this the familiar benchmark for an apparent 1-carat size.
• 6.5 mm round amethyst ≈ 0.80 ct; amethyst is less dense than diamond, so a similar diameter yields less weight.
• 6.5 mm round zircon ≈ 1.40 ct; zircon is denser, so the same diameter carries more carat weight.
• 7.0 mm round sapphire ≈ 1.50 ct; sapphires (corundum) are denser than diamonds, giving a heavier feel at similar size.
• 6.5 mm round emerald ≈ 1.10 ct; emeralds (beryl family) sit between amethyst and diamond in density, so the weight is slightly higher than for amethyst.

When shopping, compare millimetre measurements as well as carat weight to understand apparent size. If visual size matters more than carat weight, ask for millimetre dimensions or side-by-side photos to judge how a gem will wear.

Second Criterion: Clarity

A diamond is denoted as 'pure' if it has no internal or external imperfections. Determining the purity of a diamond requires an expert's trained eye, using a sufficiently large magnifying glass or a binocular - a specific microscope utilized by gemmologists. The diamond market, as BAUNAT has observed with the diamond prices evolution, holds a great deal of value in clarity, with FL (Flawless) and IF (Internally Flawless) considered the epitome of diamond quality.

Third Criterion: Colour

Diamond colour categorizations spread across a spectrum from D to Z. The closer a diamond is to being colourless, the more valuable it's considered. A perfectly colourless diamond belongs to category D, while those bearing shades of grey, brown or yellow fall under Z. Diamonds do manifest in 'fancy' colours like red, green, blue, black or purple, though these are exceptionally rare and their value falls below that of a colourless diamond.

Beyond the D–Z scale for diamonds, colour in coloured gems is assessed by three linked attributes: hue (the basic colour, for example blue or green), tone (the lightness to darkness) and saturation (the intensity or purity of the hue). Strong, vivid saturation often increases value, even when the hue is not perfectly pure. For example, an intensely saturated green emerald will generally be preferred over a paler green beryl because the vividness gives the gem more presence. Watch for colour zoning, where patches of different colour appear within one stone, and for colour-change gems that show different hues under different lights; both affect desirability and price.

Last Criterion: Cut

The cut of a diamond varies significantly, each cut enhancing the inherent brilliance of the diamond. A well-cut diamond will have numerous facets, evenly matched between the crown and the culet of the gem. The facets need to be symmetrical and proportionate to the height of the crown. 

Cutting choices change how a gem returns light. Windowing happens when proportions are too shallow and light passes through rather than reflecting back, producing a washed-out centre. A very deep cut can create dark areas and reduce apparent brightness. For coloured gems, cutters sometimes trade sparkle for deeper colour; a slightly deeper pavilion or altered facet plan can concentrate colour, improving visual appeal at the expense of some brilliance. Cabochon cutting is a deliberate choice when the goal is to show colour, asterism or chatoyancy, or when inclusions would distract in a faceted stone. In short, faceted cuts prioritise sparkle, cabochons prioritise colour and optical effects, and the right choice depends on the material and the buyer’s preference.

At BAUNAT, we're not just about selling diamonds. We believe in providing quality, efficiency, and personalized service, mirroring the values of the Smart Luxury Consumer. As industry experts, we understand the diamond prices evolution, ensuring that our customers make smart investments. Remember, when you buy from BAUNAT, you're buying more than just a diamond; you're buying years of industry expertise and a commitment to quality.