Diamond buyer's guide

Diamonds have been used in fine jewellery for thousands of years and remain the world’s most desirable gem. Nearly all diamonds are formed at depths of 150 kilometres below the earth surface, where temperatures reach 2000 degrees. Diamonds are the hardest of all gems, making them highly suitable for use in jewellery.

Each Linneys Diamond is hand selected by our certified diamond specialists. Only the finest stones pass our rigorous quality control, which is set high above the industry standard. Diamonds are graded using a system devised by the GIA (Gemological Institute of America) who are recognised as the foremost international diamond authority. This system is often colloquially referred to as “The 4 C’s” and includes Cut, Colour Clarity and Carat. The 4 C’s are designed to help you make more informed decisions on your diamond purchase.



The cut of a diamond determines its beauty. Cut is assessed based upon seven characteristics: brightness, fire, scintillation, weight, ratio, durability, symmetry and polish.  Each characteristic and its relative importance is taken into account, and a stone may be graded from Excellent to Poor. When determining a diamonds overall value, cut can be considered more important than colour, clarity and carat. A diamond that has a triple excellent cut grading is considered to be highly desirable. Diamonds of size will usually have their cut grade detailed on a Diamond Certificate.

Finest Make Diamond Deep Cut Diamond Shallow Cut Diamond
Finest Make
Linneys Diamond Benchmark
Deep Cut
Poor Light Return
Shallow Cut
Poor Light Return

Linneys diamonds are only the finest cut


The less colour a diamond exhibits, the higher its value may be. Colour grading is an internationally standardised measure based upon the GIA scale. A truly colourless diamond will be classified with the letter D. As traces of yellow or brown become visible, the scale progresses through the alphabet to Z. Diamonds graded with a D are rare and fetch a premium price tag, however, stones up to G still appear very white and are an excellent choice for most jewellery. Sometimes stones with a distinctive colour presence are chosen by individuals for their unique aesthetic. 

Diamond Colour D Diamond Colour E Diamond Colour F Diamond Colour G Diamond Colour H Diamond Colour I Diamond Colour J Diamond Colour K
Diamond Colour L Diamond Colour M Diamond Colour N Diamond Colour O Diamond Colour P Diamond Colour Q Diamond Colour R Diamond Colour S-Z

Linneys diamonds are only H colour and above


Almost all diamonds will exhibit some manner of flaw, called an inclusion, which occurs naturally within the stone. The fewer inclusions a diamond has the higher its clarity grade will be. The GIA diamond clarity scale grades diamonds from I (included) to Flawless, though most stones fall within VS (very slightly included) to SI (slightly included). The scale takes into consideration a range of factors, including the size, colour, nature, quantity and location of any inclusions. A clarity grade may look good on paper but not all stones are created equal. For instance, inclusions located close to the girdle of a stone may pose risks when being set or worn. Consider the expertise of your jeweller or dealer before making your purchase, and be wary of buying online. 

Diamond Clarity FL, IF Diamond Clarity VVS1, VVS2 Diamond Clarity VS1, VS2 Diamond Clarity SI1, SI2 Diamond Clarity I1, I2, I3
FL, IF VVS1, VVS2 VS1,VS2 SI1, SI2 I1, I2, I3


Carat refers to the weight of a diamond or other gemstone. The word ‘Carat’ comes from the ancient carob seed, which was used by historic gem traders as a counter weight in scales. A carat is equal to 0.2 grams and is divided into 100 points. Diamonds with a high carat weight are rare, and can fetch considerably higher prices than smaller stones. When purchasing a diamond, be sure to consider all the 4 C’s of diamond quality, not just the size of a stone.

Diamond Carat 5.00 Diamond Carat 4.00 Diamond Carat 3.00 Diamond Carat 2.00 Diamond Carat 1.5 Diamond Carat 1.00 Diamond Carat 0.75 Diamond Carat 0.50 Diamond Carat 0.25
5.00 4.00 3.00 2.00 1.50 1.00 0.75 0.50 0.25

Commitment to Quality Ethical Diamonds

Linneys are committed to selecting only premium quality diamonds from guaranteed sources.  The Kimberley Process is a United Nations mandated forum, with a focus on stemming the flow of conflict diamonds into the international market. When purchasing a diamond from Linneys, you can be assured you a buying a quality, hand selected stone from a conflict free source.