Diamonds, renowned for their exceptional hardness, brilliance, and enduring beauty, hold a prominent place in the world of gemstones. While often associated with love and commitment, diamonds are also intrinsically linked to the month of April as a traditional birthstone. This article will delve into the characteristics of diamonds, exploring their gemological properties, the significance of diamond grading, and the role of certification in ensuring quality and authenticity.
Diamond Properties and Formation
Diamonds are composed of pure carbon, crystallized in a cubic structure. This unique atomic arrangement is responsible for the gem’s exceptional hardness, registering a 10 on the Mohs scale – the highest possible rating. This extreme hardness makes diamonds exceptionally durable and resistant to scratching, contributing to their lasting appeal.
The formation of diamonds occurs deep within the Earth’s mantle, under conditions of extreme pressure and high temperature. These diamonds are then brought to the surface through volcanic eruptions, embedded within a rock called kimberlite. The diamond’s depth is its height from the bottom tip, or culet, to the table of the gem. The table is the top facet, or the flat surface on the top of the diamond. The girdle is the horizontal midsection and widest part of a diamond.
The 4Cs: Evaluating Diamond Quality
The quality of a diamond is assessed based on the “4Cs”: Carat, Clarity, Color, and Cut. These criteria provide a standardized framework for evaluating a diamond’s value and beauty.
Carat refers to the diamond’s weight. One carat is equal to 0.2 grams. Larger diamonds are rarer and generally more valuable, though price increases are not linear with carat weight.
Clarity grading assesses the presence of internal inclusions and external blemishes. The clarity grading scale ranges from Internally Flawless (IF) or Flawless (F) – indicating no inclusions or blemishes visible under 10x magnification – to Included (I3), signifying significant inclusions. Diamonds graded as Slightly or Very Slightly Included can still be beautiful, but require individual assessment.
Color in diamonds refers to the absence of color. The GIA (Gemological Institute of America) color scale ranges from D (colorless) to Z (light yellow or brown). Colorless diamonds are the most desirable and valuable.
Cut is arguably the most important of the 4Cs, as it directly impacts a diamond’s brilliance, fire, and scintillation. Cut refers to the proportions, symmetry, and polish of the diamond. A well-cut diamond will reflect light internally and disperse it through the top, creating a dazzling display. Polish is rated excellent, very good, good, fair or poor, depending on the condition of the diamond’s surface. Symmetry is assessed on the precision of the diamond’s cut, its symmetrical arrangement and the placement of its facets, and is also evaluated on a scale ranging from excellent to poor.
Diamond Cut and Shape
Diamonds are cut into a variety of shapes, each offering a unique aesthetic appeal. Common diamond shapes include: Round, Princess-Cut, Emerald, Square Emerald, Oval, Radiant, Pear, Heart-Shaped, Marquise, and Cushion. Shape selection is a personal choice, best made by considering the preferences of the recipient.
Diamond Fluorescence
Fluorescence refers to the glow a diamond emits when exposed to ultraviolet light. A diamond’s fluorescence can range from none to very strong, and may appear in colors such as blue, green, pink, yellow, orange, or red.
Diamond Certification and Grading Laboratories
Ensuring the authenticity and quality of a diamond requires independent certification from reputable gemological laboratories. The Gemological Institute of America (GIA) is widely considered the industry standard for diamond grading. Any diamond submitted to G.I.A. is ensured to have reliable and consistent grading, with 3-6 separate gemologists individually grading each stone for an accurate final grade. G.I.A. grading reports contain a full description of the diamond and a plotting of the clarity characteristics. The G.I.A. Dossier provides full details but omits the plotting. Both reports include a unique serial number laser-inscribed on the diamond’s girdle for verification.
Other respected certification laboratories include the International Gemological Institute (IGI) and the Gemological Science International (GSI). Both IGI and GSI follow GIA standards. GSI is an independent gemological laboratory that provides professional gemstone identification, grading and appraisal services exclusively to the fine jewelry industry. Each diamond examined by GSI is assessed by a minimum of four gemologists for color and clarity grading.
The American Gem Society (AGS) is also known for grading Ideal-Cut round diamonds, adhering to high standards that surpass others in color, clarity, and cut. AGS Ideal-Cut diamonds are highly sought after.
Light Performance and GemEx Systems
GemEx Systems provides certification on the light performance of a diamond, measuring its fire, sparkle, and brilliance through a process known as the “Return of Light.” The GemEx BrillianceScope® Analyzer uses spectrophotometer technology to assess a diamond’s white light (brilliance), color light (fire), and scintillation (sparkle), rating each against other diamonds of the same shape. Superior performance in any of these categories contributes to a beautiful diamond.
Diamond Settings
Diamonds can be set in a variety of settings, each influencing the overall appearance and security of the stone. Some settings are limited in the shapes of diamonds they can accommodate.
Conclusion
Diamonds represent a pinnacle of natural beauty and enduring value. Their exceptional hardness, brilliance, and versatility have made them a cherished gemstone for centuries. Understanding the 4Cs, the importance of certification, and the various diamond shapes allows for informed decision-making when selecting this remarkable gem. The enduring appeal of diamonds ensures their continued prominence in the world of jewelry and as a symbol of lasting affection.