Diamonds have always been a girl's best friend. For the elegance, brilliance, and durability, diamonds are the most luxury goods and the most appreciated romantic gifts. A diamond must have a perfect colour, clarity, and a good cut to be a diamond of high quality and value. Diamonds are crystals of carbon heated and pressed more tham 3 billion years due to volcanic activity. Most of diamonds come from South Africa and Russia. Diamonds are located in the earth, 200 miles below the surface, and hard to mine and processing. Cutting and polishing require good skills and there are few specialized centers round the world: Ajax (Holland), Antwerp ( Belgium), Mumbai (India), Tel Aviv (Israel), New York, Johannesburg (South Africa). De Beers is the biggest company that brings diamonds from mine to your home.

To be sure about the quality, ask for seing a certificate issued by an independent accredited lab that reports the quality of a diamond, such following 4 Cs, shape, and proportions.

• Cut: a diamond must release an inner brilliance, thanks to a good cut diamond's design, the symmetry and the polish of the stone.
• Colour: a diamond must be white. If you see a light yellow colour, the stone has less value. Diamonds are graded on a colour scale from D to Z. D is for expensive and rare stones and absence of colour, while Z is for cheap stones with presence of other colours. Anyway the value of a stone depends on the rarity, red or green are more expensive than yellow stones. Also saturation influences the price.
• Clarity: a good diamomds has no flaws (internal inclusions, external blemishes). The clarity scale for diamonds are graded from F = flawless, good stone, to I = imperfect stone.
• Carat: the carat weight is the size for diamonds. One carat is 200mg. or 100 points. off course, because of big diamonds are rare, they cost more per carat compared to small diamonds.

We can find diamonds in the earth, but even if a diamond has perfect color and clarity, it won't be sparkle before being cutting and polishing. The cut of a diamond determines its value, the cut is made using a mathematical formula. Because the reflection of a ray of light, worldwide named brilliance, is the most important factor to evaluate the value of a diamond, the most famous cut design is the round brilliant that, with its 58 polished facets, maximizes brilliance. Other shapes of a diamond could be emerald, oval and square. To determine the value of a diamond, we must include the exact round of the stone, the depth, and width.

In the quality scale, we have ideal, excellent, very good, good, fair, poor. In an ideal (and also excellent) diamond, all light that enters into the stone is reflected back, thanks to the right proportions of the cut, firstly the depth / diameter ratio and the depth / diameter of the top facet of the diamond rate. In a brilliant cut diamond we found 32 facets plus the table above the girdle (crown), and 24 facets plus the culet below the girdle (pavilion). To check cut diamond quality, use a diffused natural light. Well cut diamonds are brilliant refracting rainbow colors, while bad cut diamonds could have dark center or a white circle round the table.

As described above, each diamond has the ideal proportions between table diameter in %, crown angle in degrees, pavilion depth in %, girdle thickness in %, and the culet. For a round brilliant, the ideal cut is as follows:

• table diameter: 53-57%
• crown angle: 34-35 degrees
• pavilion depth: 42-43%
• girdle thickness: thin, medium, thick
• culet: point, small, or medium
• total depth: 60-62% of the diameter of the stone

Before purchasing a diamond, ask for all above specifications, avoid people who offer an ideal cut diamond and show you only table diameter and depth. Most small diamonds on the market are without certification, you must trust the seller or check the brilliant of the stone.

The value of a diamond depends also on the absence or little presence of flaws on the surface or internal. All diamonds have some flaws, but the fewer these flaws, the more valuable the diamond, because these flaws don't allow the perfect passage of light through the diamond. Internal flaws, called inclusions, are usually caused during formation due to crystals, small bubbles, minerals absorbed into the diamond.

At the top of the diamond clarity scale,we find flawless diamonds (FL), there is no presence of external flaws, and internal flaws are no visible under 10x magnification. Then we find internally flawless diamonds (IF), just small imperfection on the surface, and without internal inclusions visible under 10x magnification. In the diamond clarity scale we find: very slightly included diamonds (VVS and VS) with very small inclusions, and slightly included diamonds (SI) with inclusions or surface imperfections visible under 10x magnification. At the end of the scale we found imperfect diamonds (I1, I2, I3), I3 has large mperfections seen also without 10x magnification.

The colour report the presence or absence of colours in diamonds, the absence of colurs give diamonds bigger value. The diamond colour scale begins with D for colorless, the best diamonds, and arrive to Z. Under H, it is visible only a trace of colour, from R to Z diamonds appear yellow. Although white diamonds are the best, lately are becoming trendy fancy colored diamonds in red, blue, green colours. To value this diamond, we must see the saturation and purity of the colour, reds and greens are rarer than yellows and browns.

Thanks to irradiation and heating a poor diamond can change its natural colour becoming green or red (the most value diamonds becuse rare), but colored diamonds by chemical process have a lower value than natural fancy diamonds.

Carat is the most common measure to determine the quality of a diamond, the weight of a diamond. Carat name come from carob seeds used in the past as measure unit to determine weight of goods.

1 carat = 0,2 grams = 100 points

The exact size of a diamond depends on carat and girdle diameter, for an ideal round brilliant, the proportion should be:

• 1/4 carat = 4.1 mm
• half carat = 5.15 mm
• 3/4 carat = 5,9 mm
• 1 carat = 6,5 mm
• 10 carats = 14 mm

After purchasing a diamond, you have also to choose the right setting for the stone to maximize value and beautiful, the most popular are:

• Ballerina: very popular setting for rings, a center stone is surrounded by baguettes (small stones) like a ballerina's tutu
• Cluster: used for rings and earrings, many small stones surround a bigger center stone
• Flush: used for rings, the diamond is plunged in the mounting, you can see only the surface, excellent dimond protection
• Illusion: used in rings, the girdle is surrounded by a light mounting
• Invisible: for tennis bracelets, stones are placed in rows
• Prong: used for solitaires, the stone is anchored to the mounting thanks to 4 or 6 prongs placed round it. This solution maximizes brilliance, and the stone will appear bigger

Diamonds are the hardest metals on the planet, anyway must be handled with care, and stored separately without touching diamonds. A diamond could scratch other diamonds if stored in a wrong way, so to preserve the life and beauty of a diamond for long time doing as follows:

• Store each diamond in a fabric of linen or in a box with compartments, avoid to put more diamonds in touch each others
• Avoid to wear diamonds during hard everyday activity, because the stone could come out from the setting
• Avoid diamonds will be in touch with chemical agents, they could discolor the mounting
• Clean your diamond frequently, with a jewelry cleaner or warm water with delicate soap and a soft toothbrush
• If possible let professionals clean your diamonds