Diamond Clarity

All mined diamond consists of flaws. They might  form inside diamond known as inclusions,  and surface irregularities called blemishes .Together , they’re known as clarity characteristics. Diamond clarity is the absence of inclusion and blemishes.

Blemishes include scratches and nicks on a diamond’s surface. Inclusions are inside, or they might extend into the interior from the surface of the stone.

Clarity characteristics might have negative influence on diamond’s value, but they have positive effect as well:

. They help gemologist separate diamond from simulants, Inclusions in diamonds often have a        different appearance from inclusions in simulants.

·       ..  No two diamonds have exactly same clarity characteristics; they can help identify individuals stones.

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         .  Provides valuable information about its formation.

     

Inclusions normally have more impacts on a stone’s beauty and then blemishes. That’s because many blemishes are easy to remove. It’s possible to eradicate an inclusion that’s close to the surface, but that could cause and reduction in the diamond’s weight. Recutting and repolishing a diamond to remove a blemish, on the other hand, often increase its value. The impact of any weight loss is usually offset by the improved clarity.

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Cutlet size

Cutlet size depends upon different cuts. All fancy cuts have cutlet but standard round brilliance cut don’t have it. Main purpose of cutlet is to protect the bottom of gems against accidental chipping or abrasion. Most cutlet size are viewed visually by graders, medium size cutlet can be seen through 10x magnification but not with unaided eye.

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Crown Angle

The crown angle is the angle that’s formed where the bezel facets meet the girdle plane. Most diamonds have crown angles range between 25 and 35 degree angle. Diamond with crown angles shallower than 25 can be quite bright, but they are more susceptible to damage than stones with higher crowns.

Diamonds with shallow crowns should be set in mounting that protect the girdle area, like bezel setting, which surround the sound with a rim of precious metal. Diamonds with lower crown angle are better suited for use in jewelry where they’re less vulnerable to damage, like earrings and pendants.

It has been a challenge for a diamond cutter to cut in a shallow crown & pavilion angle in other to get largest girdle diameter and the highest possible weight retention. They also tend to have larger table percentages and thin girdles.

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Diamond Stability

Stability refers how well a diamond resists temperature change and chemicals. Diamonds are  very stable until and unless sudden, extreme temperature changes occurs. Those changes can cause thermal shock, which can create new fractures or cause existing one to spread.

Diamonds burn : 1562 degree farenheit / 850 degree Celsius

Apperance : looks white and cloudy

                                         

 A house fire caused the white, cloudy appearance of the diamond (left). The stone was recut to remove the burned area, reducing the diamond's  size but leaving no sign that it was ever damaged (right).

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Diamond Toughness

Diamond toughness is related with how well the gem can survive and impact – resist breaking, chipping, or cracking. The formation of diamond affects the physical and optical quality. Diamond form under extreme temperature and pressure, they bond to each other more tightly in some directions than they do in others.

Diamonds are tougher in the direction where atoms are tightly together, less tough - where there are not so tightly bonded. The weakest diamond is one where the atoms are far apart. It is easier to break in that direction, which is called cleavage direction. But even after cutting process, a hard blow can cleave or fracture a diamond. This can happen during setting process or even after it’s worn.

The bonding of  weak atoms in Diamond (Left) teends to cleave after recutting diamond can regain it overall beauty and value (Right).

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