What is a diamond?

The name diamond refers to its hardness (Greek - adamas, the unconquerable). There is nothing comparable to its hardness making it nearly imperishable. Its cutting resistance is 140 times greater than that of ruby and sapphire, the gemstones next in hardness. (It is the hardest transparent substance known to man however, impact may cause damage to a diamond.)

Even though the diamond is the hardest of all gemstones, it is the simplest in composition. It is common carbon, like the graphite in a lead pencil, yet has a melting point of approximately 4,000 degrees centigrade, which is two and a half times greater than the melting point of steel. Billions of years ago, the elemental forces of heat and pressure miraculously transformed the carbon into diamond in the cauldron of boiling magma that lay deep below the earth's surface. The volcanic mass in which this crystallization took place, then thrust upwards and broke through the earth's surface to cool in kimberlite or lamproite pipes. It is in these pipes that most diamonds are found today.

A diamond is judged by four distinct factors that combine in a number of ways to arrive at its value. These are called the 4C's:

Cut

Of all the 4C's, cut is the one most directly influenced by man and is the most important factor when choosing a diamond. It is how a diamond is cut that determines its fire and its brilliance. Round brilliant cut diamonds are cut with 58 facets (including culet), and a good proportion of cut has more scintillation and more sparkle.

The shape of the diamond, however, is largely a matter of personal preference. It is the skill of a master cutter that allows the diamond to be cut in such a way as to permit the maximum amount of light to be reflected through the diamond.

At Jan Logan, all our diamonds are carefully selected to ensure maximum brilliance.

Colour

Colour quality is critical. A diamond's beauty and value will usually increase dramatically the more colourless (white) it is. The colour grading scale ranges from totally colourless (D) through to light yellow (Z). The differences between one grade and another are very subtle and must be graded under controlled lighting conditions. Rare stones of exceptional colour - green, red, blue, pink or amber are known as fancies.

At Jan Logan when choosing a diamond we recommend a F-H colour to combine both whiteness and value.

Clarity

Almost all diamonds contain minute traces of non-crystallized carbon called inclusions - they are nature's finger print and make every diamond quite unique. Most are not discernible to the naked eye and require magnification to become apparent.

Inclusions are ranked on a scale of perfection, known as clarity, ranging from F (Flawless) to (I) Included, based on the visibility of a magnification of 10x. It should be noted diamonds that have a clarity rating of SI2 and above have inclusions that are not visible to the naked eye.

At Jan Logan we recommend a VS-SI clarity which combines both quality and value for money.

Carat

As with all precious stones, the weight of a diamond is expressed in carats. One carat is divided into 100 'points' so that a diamond of 25 points is described as quarter of a carat or 0.25 carats.

Size is the most obvious factor in determining the value of a diamond but two diamonds of equal weight can have very different values depending on their cut, colour and clarity. However, as a diamond increases in size it also increases in value for the simple reason that large stones are rarer than small ones.

At Jan Logan our sales consultants are highly trained to help you weigh all of the factors to arrive at the best combination of cut, colour, clarity and carat for your engagement ring.

Shape

The shape of a diamond, along with design, will largely affect the look and feel of a ring. All Jan Logan stones, no matter their shape, have been cut to maximize their brilliance.

At Jan Logan, we specialise in designing settings for the brilliant, emerald and princess cut diamonds. However, whichever shape you choose is entirely a matter of personal taste.

Guarantee

All engagement rings purchased at Jan Logan will come with a written valuation/certificate that guarantees the quality of the stone.

Design

At Jan Logan we consider the design of an engagement ring is equally as important as the quality of the diamond. The thickness of the shank, the height of the stone and the overall balance of the ring are vital in creating the correct 'look' and 'feel' of a ring. Our designs, whilst contemporary, maintain a classic 'timeless' element. It is these attributes that will mean your ring will stand the test of time and won't be subject to the vagaries of today's fashion. We would like the design and style of the ring that you purchase from Jan Logan to last forever.