Diamond is one of the best-known and most sought-after gemstones. Diamonds have been known to mankind and used as decorative items since ancient times; some of the earliest references can be traced to India. Renowned for being the hardest substance on earth, its sparkling fire, durability, and rarity make Diamond the most prized of all gems.
Renowned for being the hardest substance on earth, its sparkling fire, durability, and rarity make Diamond the most prized of all gems.
The hardness of diamond and its high dispersion of light giving the diamond its characteristic “fire” – make it useful for industrial applications and desirable as jewellery. Diamonds are such a highly traded commodity that multiple organizations have been created for grading and certifying them based on the four Cs, which are colour, cut, clarity, and carat. Other characteristics, such as presence or lack of fluorescence, also affect the desirability and thus the value of a diamond used for jewellery.
Stock Sizes: Available in both G/H SI and F/G VS grades
Round: 0.07mm – 6.5mm
Princess Cut: 1.00mm – 5mm
Baguette: 2×1.mm – 6x3mm
Marquise: 3x2mm – 6x3mm
Pear shape: 3x2mm – 6x4mm
A wide range of single stones are available including GIA, IGI, HRD and EGL certificated goods. Also available in Black, Blue, Yellow and Green treated colours.
Chemical Formula: C (Carbon)
Crystal Structure: Cubic (or isometric)
Colour: All colours. Diamonds most commonly occur in shades of yellow, grey and brown. The rarer stones are colourless and the rarest are reds, blues, pinks, greens in intense saturation.
Hardness: 10 on Moh`s scale
Refractive Index: 2.417 to 2.419
Specific Gravity: 3.50 to 3.53
Cleavage: Four directions; perfect
Treatments: See below
Coating enhances a diamond’s colour by masking an undesirable body colour with an ultra-thin layer of chemicals or plastics. Another form of coating involves applying a thin film of synthetic diamond to the surface of a diamond simulant, giving it certain characteristics of a real diamond.
HPHT stands for a high-pressure, high-temperature. The process is an effective tool for changing the colour of certain diamonds, making them colourless, pink, blue, green, yellowish green, or yellow. Outside of a well-equipped grading laboratory, this form of treatment is virtually undetectable.
There are two main techniques for improving a diamond’s clarity; laser drilling and fracture filling.
Laser drilling is commonly used to remove small dark inclusions. The laser bores a small hole into the diamond’s interior and burns away the inclusion, or creates a channel through which a bleaching agent can be introduced to improve the inclusion’s appearance.
Fracture filling hides white fractures in a diamond called “feathers.” A glass-like substance is injected into the fracture to make it less visible and to improve the stone’s apparent clarity. Because the filling may be damaged or removed during routine cleaning and repair, the technique is controversial. Good fracture filling is very subtle, and so examination by a skilled diamond grader is necessary to detect its presence in a stone.
Care: Diamonds are remarkable gemstones which require very little maintenance. They can be wiped clean using plain soapy water and a soft cloth. Ultrasonic cleaners are generally considered safe, but always take care when using this cleaning method, especially with fragile settings. Diamonds are typically insensitive to chemical reactions, but the same cannot be said for the mounting or prongs holding the diamond in place, so avoid harsh chemicals when cleaning diamond jewellery.
Diamond facets can be etched on under high temperatures, so avoid extreme heat and take extra care when soldering diamond jewellery.