Diamonds and Pearls
Diamonds or pearls?
Both diamonds and pearls are very beautiful and make lovely jewellery gifts. When considering either, it is worth knowing some important points about both before you make your purchase.
About Diamonds
Diamonds were formed about 70 million years ago – due to their hardness, strength and transparency they have become highly sought after and treasured gem stones.
Diamond Certification
All jewellery or stone with a Certificated Diamond are independently and individually graded for Colour and Clarity by the Birmingham Assay Office, IGI, IGL or GIA and come with the appropriate grading certificate at no extra cost.
Who provides diamond certification?
Diamond certificates are issued by independent gemological laboratories. There are several grading laboratories, the most prominent being: the International Gemological Institute (IGI); the Gemological Institute of America (GIA); the American Gem Society (AGS); the European Gemological Laboratories (EGL) and GemEx Systems. A completed certificate includes an analysis of the diamond’s dimensions, clarity, colour, polish, symmetry, and other characteristics. Round diamonds will also include a cut grade on the report.
GIA Certificate (Gem Institute of America)
The GIA set the standard for diamond grading and gemmological identification, and their grading system serves as the international gem and jewellery industry’s benchmark. A dossier is issued for diamonds under 1 carat. Each diamond with a GIA Diamond Report is laser inscribed with the report number. The report includes information about the shape and cutting style, its dimensions, weight to the nearest hundredth of a carat, depth (for round diamonds) and/or width (for fancy shapes), the thickness of girdle and its polish and symmetry. It will also give information about the clarity grade determined under 10x magnification, the colour of the diamond colour and strength of colour viewed under UV light. The document will also include additional diamond characteristics not mentioned in the report.
AGSL Diamond Quality Document (American Gem Society Laboratory) / GCAL (Gem Certification & Assurance Laboratory). A Quality Document, from the American Gem Society Laboratories, is respected by the jewellery industry as a document of authenticated quality. The AGSL uses a grading system that ranks cut, colour, and clarity on a zero to ten scale, with zero signifying the rarest and most desirable and ten indicating the least desirable. A Certificate of Authenticity, issued by the Gem Certification & Assurance Lab (GCAL), also serves as verification of your diamond’s quality. GCAL warrants that each diamond meets the grades and measurements noted in the GIA or AGSL grading report.
Diamond Quality
The quality of a diamond depends on its clarity, carat, colour, cut and shape.
Diamond Clarity
Most diamonds have a few imperfections and are yellow, although this is many are not visible to the naked eye.
Diamonds that are absolutely clear are the most sought-after and therefore the most expensive. Many diamonds have small scratches, trace minerals or other tiny characteristics that can detract from the pure beauty of the diamond. We would recommend that you look for a diamond, which to the naked eye, appears to have no imperfections.
Diamond Weight
A diamonds’ weight is measured in carat – one carat is 0.2grams. Most diamonds are weighed in hundredths of a carat and it is only a rare few over 1 carat which prove to be extremely valuable. For example, a quarter carat would be 25points or.25 carats.
Diamond Cut
It is the cut of a diamond that can determine its final value. The width and depth can have an effect on how light travels within the diamond, and how it exits in the form of brilliance. If cut too shallow, light can be lost and if cut too high, light can escape lessening the brilliance of the diamond. Whether large or small, cut is critical since releasing a diamond’s maximum potential for beauty and brilliance is an art. The polish and symmetry of the diamond cut is also very important. If either are not done well, the light can fracture as it travels through the diamond affecting its brilliance. A well cut diamond is one that maximizes the beauty and brilliance of the stone and is not to be confused with shape.
Pearls – a brief synopsis
A pearl is the only gemstone that is formed within a living animal. They are formed in an oyster or mollusk. Now, most pearls are cultured – the oyster or mollusk has had a ‘foreign body’ artificially injected into it, whereby it secretes a substance, similar to that of its shell around the intruder – thus a pearl is slowly built. Without this procedure, natural pearls would firstly, be beyond the reach of most except the very wealthy, and secondly, the demand for them would have resulted without doubt to the extinction of the oyster or mollusk responsible for its creation. There are two major pearl grading systems although these can be misrepresented by some pearl sellers so you should apply this with caution. When purchasing a pearl, ask to see in writing the Grade and the standards that the seller pertains to this standard so that you are not misled.
Different systems are applied to different pearls (depending on where they were grown). They apply to their lustre and the appearance of any amount of surface defects. Another point to consider, is also Nacre – the thickness of this will determine the strength and durability of your pearl. It is generally accepted that a minimum of 0.8mm of lacre thickness is acceptable. This was defined by the Government of French Polynesia and it is fairly accepted as a good benchmark for anyone purchasing a pearl.
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