Loose Diamonds - Some Tips
REMEMBER: The 6 C's of Diamonds!
CUT, CLARITY, COLOUR, CARAT, CONFIDENCE and COST.
The cut refers to the shape of the diamond, based on the angles and proportions that cause light to reflect between the facets. Diamond shapes range from round cuts and hearts to pear and oval. The traditional shape is round brilliant with 58 facets. Other popular shapes are marquise, emerald and princess.
The cut of a diamond consists of three factors: depth, polish and grade.
Depth How deep the stone has been cut. If a stone has been cut too shallow or too deep, the diamond will lose light through the bottom or sides, which will cause less sparkle.
Polish Determines the diamonds's brilliance. A poor polish or rough facets will reduce this, and thus its value.
Grade - A standard grading report describes the cut of a diamond, based on the shape or outline and the pattern made by the facet arrangement (also known as the cutting style).
CARAT
Carat: The weight, and thus the size, of a diamond is measured by carat. A carat is equal to 0.2gm, or 200mgm. A carat is divided into 100 smaller units called points. For example, three-quarters of a carat is 75 points. The average size of most engagement-ring diamonds is somewhere between one carat and half a carat.
Do not confuse carats with karats, the unit of purity for gold.
1 carat = 100 points = 200 milligrams (one fifth of a gram)
The cut and setting can often make a diamond look bigger than its carat weight so examine all four standard measurements before buying.
COLOUR
Colour: All diamonds possess trace amounts of yellow or brown the most valuable diamonds tend to be the colourless diamonds. However, very deeply coloured diamonds can actually cost more. These 'fancy diamonds' (also called Z+ diamonds) are rare, and can be found in yellow, blue, green, black, red and pink.
The most valuable and rare colour is white i.e. colourless. Jewellers grade totally colourless diamonds with a 'D'. The scale moves from 'D' to 'Z' and, between these two extremes, diamonds will display subtly different coloured tones.
CLARITY
Clarity: Most diamonds have inclusions (small mineral traces or flaws). These are often undetectable to the unassisted eye. They devalue the stone. They can also affect the flow of light through a diamond, which reduces the brilliance. Flawless diamonds are rare and very expensive.
As long as the stone is graded SI1 (Slightly Included 1) or better you should be all right. The best and most expensive is IF, or Internally Flawless; worst is I3, or Imperfect 3.
CERTIFICATION
Certifcation: Certification (official documents issued by third-party gemological labs) states the details about each gem (as a minimum, a grading report of the 4 Cs - cut, carat, colour and clarity). It's independent of market value. The most internationally recognised are by the Gemmological Institute of America (GIA). Other popular certificates include HRD, IGL, EGL and AGS.
The fee for a grading certificate varies depending upon the carat. For a quote, contact a specific lab. You can organise your own certificate rather than accepting the jeweller's recommendation.
Ask if the stone is a genuine diamond or if it is a cubic zirconia, or other synthetic substance. Keep your correspondence. Cubic zirconia is also not as durable as a diamond and may show signs of wear.
Take the stone to a trusted jeweller, and have him examine it thoroughly.
Recently, some of the best imitation diamonds are made of moissanite. Even experts have a hard time distinguishing them. Moissanite sells for about one-tenth the price of diamonds.
Diamonds can also be artificially treated, most commonly fracture filled, irradiated or laser treated. This is legal, as long as it is disclosed to the buyer, but if you want a 'real' and untreated diamond, beware terms such as "clarity enhanced".
Warnings:
When buying 'diamonds' online or stones you have not seen or had appraised independently, make sure the diamond comes with a grading report provided by an independent lab like the GIA.
Look inside the diamond. A fake stone is always clear, no inclusions.
COST
Cost: Punters are told that one to two months' salary is the norm. This seems to stem from De Beers' publicity. Spend what you like and can reasonably afford.
CONFIDENCE Confidence: is in a reliable jeweller. Buy from someone you trust, or a stone commended by them. Is the shop willing to sell you diamonds with a reputable gemmological cert.? Does the shop have a good, long-standing, local reputation? What guarantees does it offer?
REMEMBER: The 6 C's of Diamonds!
CUT, CLARITY, COLOUR, CARAT, CONFIDENCE and COST.
Then: MAINTENANCE
Diamonds should be stored individually in soft cloth pouches to prevent the stones from hitting each other and chipping.
Clean them occasionally in soap and water. Let the jewel dry in the air, then polish it with a soft cloth. For more resistant marks, use a soft brush with a weak solution of one part ammonia and four parts water.
Jewellers can also clean diamonds and gems for you, using steam or ultrasound. WARNING: ultrasound can aggravate internal flaws so make sure the jeweller knows what hes doing. |
