Gemstone guidance

Diamonds and the 4 C's


There are Various characteristics of diamonds are graded and categorized by the diamond industry. To understand diamonds is to first learn about the "four C's" of diamonds - the four characteristics that are considered the most important in determining a diamond's value:

  • Cut

    Cut is probably the most important, and most challenging, of the four Cs to understand. The brilliance of a diamond depends heavily on its cut.

  • Clarity

    Most diamonds contain some inner flaws, or inclusions, that occur during the formation process. The visibility, number and size of these inclusions determine what is called the clarity of a diamond. Diamonds that are clear create more brilliance, and thus are more highly prized, and priced.

  • Colour

    Colourless diamonds are the most desirable since they allow the most refraction of light (sparkle). Off white diamonds absorb light, inhibiting brilliance.

  • Carat Weight

    A carat is the unit of weight by which a diamond is measured. Because large diamonds are found less commonly than small diamonds, the price of a diamond raises exponentially to its size. and how it affects the appearance of a diamond.

The Fifth C: Certificates

The diamond certificate, which is sometimes called a grading report, is a complete evaluation of your diamond that has been performed by a qualified professional with the help of special gemological instruments. Each stone bears its own recognizable, individual characteristics, which is listed on the certificate.

Sapphires and Rubies


These two beautiful gemstones are becoming so sought after by the world’s cleverest money that I am asked regularly by private clients to source these two gems for their collections. Again with these gems, laboratory certificates are essential to show two points that are of vital importance.  The first is where the stone comes from, this is very important as the three main areas are;


Kashmir which is the holy grail of sapphires and no longer produces hardly any sapphires, these stones are highly prized and rocket in value each and every year, they are extremely rare.  The blue is mesmerising in its beauty.  Kashmir Sapphires are another example of buying the very best and seeing the value grow. These sapphires are not only the rarest but are also considered the world’s most beautiful due to their colour and purity. It is generally accepted that Kashmir sapphires have set the standard by which all other blue sapphires are evaluated.

These sapphires have medium to medium-dark tones of violet-blue to blue and are known for their violet-blue colour and “velvety” or “sleepy” transparency (caused by fine rutile needle inclusions called “silk”). Unfortunately, the vast majority of Kashmir sapphires found today are in antique or vintage jewellery


The next area is Burma, although predominantly famous for it’s Ruby's, Burma produced sapphires of outstanding beauty which it supplies have sadly all but dried up, Making these stones highly desirable and highly valuable. Trading in gemstones is illegal in Burma today. Present day Myanmar was once known as Burma and is a well known source of the world’s top quality rubies as well as fine sapphires. Sapphires found in this region can be very large and come in various colours including: colourless, purple, violet, blue, green and pink. Burmese sapphires are different from Kashmir sapphires in their tone and colour distribution. Kashmir sapphires are medium to medium-dark and Burmese sapphires can range from medium to darker tones. Hues in Burmese sapphires are similar to Kashmir and Sri Lankan sapphires but are more evenly distributed and are often called “electric blue” in colour.


Is Ceylon or Sri Lanka, this area still produces natural Sapphires though not in great numbers. These gems are highly prized when excellent colour and clarity are found. The second point on a sapphire certificate is whether the stone has been treated by heat, to artificially enhance its colour and clarity and whether the stone has none or minor heat treatment or more significant heat treatment, this applies to sapphires and rubies and greatly reduces value when found. These sapphires are still called Ceylon Sapphires and are highly prized by collectors and jewellery lovers for their gorgeous luminosity and brilliance. Most of the fine quality sapphires available today come from Sri Lanka, which produce a wide range of beautiful blues with rich saturated hues. Other colours from Sri Lanka include vibrant pinks and violets (more rare than blue), and the pinkish orange sapphire called “Padparadscha” that is only found in Sri Lanka. The deep blue colours of Ceylon sapphires are considered among the finest sapphires available and are known for their transparent surface that glitters. These sapphires are ultimately known for their higher clarity, rutile silk needles, and fingerprint inclusions. Sri Lanka produces an estimated 60% blue, 35% yellow and orange, and 15% pink or purple coloured sapphires.

The same applies to rubies but the origin is almost always required to be from Burma. Burma no longer produces Rubies.  It has produced the most fabulous red rubies and these stones are rising in value year on year.  They are extremely rare when the right colour and clarity are present. There is no reason why you could not buy these types of gemstones at the right money with the correct advice.

When buying rubies, the best colour to look for is a pigeon blood coulour but stones of this quality are rare and very expensive. Thailand, Tanzania and Madagascar (formerly the Malagasy Republic) also produce stones but rarely of the quality of the Burmese stones. Sri Lanka, which has the greatest variety of gemstones, also provides rubies, most of which are pale, but occasionally intense reds are discovered. Pale red colours are actually classified as pink sapphire. New sources of stones are being discovered with regularity.

Rubies are 'the' investment stone. Large crystals over five carats are very rare and a lot is lost in cutting, due to colour variations. Rubies often contain inclusions called 'silk', caused by needle-like crystals of rutile. The inclusions sometimes form in such a way as to produce what is known as a star ruby. These are cut en cabochon orientated to display the star. They are highly prized and expensive.



Emerald is a member of the Beryl family, which consists of Beryl (commonly green)

Only green Beryl containing chromium is classed as emerald, because it is this impurity that gives the gem its beautiful colour. Emerald is rarely free of inclusions and these are sometimes referred to as the 'garden' of the stone. Colour is all-important in emerald, inclusions are within the gem are secondary. Look through the table (top gemstone) of one with a magnifying glass and explore within, it can be a wonderful experience. A perfect emerald can outrank a diamond in value.

The current sources of emerald are Colombia, Zambia Brazil, Russia, Australia, South Africa, India, and Afghanistan plus a few minor sources. Recently, finds of gem quality have been made in Canada. A rare form of emerald, the Trapiche is only found in Colombia. Its name comes from the spoked Cogwheel used to grind sugarcane, as the stone displays a spoke-like pattern, which gives a six-pointed star effect. Large emeralds are very rare, particularly those of good colour. One of the biggest found in the early 19th century in Colombia was the 'Devonshire', which weighed in at 1383.95 carats uncut.

Colombia is the very best origin. When purchasing a Colombian emerald before it can be certified of the origin of Colombia it must be examined an approved gemological laboratory. It must have the origin of Colombia stated on the certification of the laboratory.

Zambia is the second best of origins in the world it also must be certified by a gemological laboratory it also must have the origin of Zambia stated on the certification of the laboratory.

When treatment is applied to an emerald it is known as oiling. Most emeralds have undergone some treatment as when they are first mined they placed in an epoxy resin. Oils are often used to improve the appearance. When oiling has been applied it will be stated on the gemological laboratory certificate.

Natural pearls


Pearls are now one of the very best performers when it comes to annual appreciation, not to mention one of the most beautiful naturally occurring gemstones in the world. These wondrous gems usually come in the form of pearl necklaces or earrings and are becoming so sought after that I would probably advise natural pearls as the best buy you could ever consider.

The Natural pearl has to be accompanied by a respected laboratory report that will state the pearls have been x-rayed and are found to be natural. A cultured pearl always has a seed in the middle of the pearl which will have been inserted into the oyster. To make the pearl grow a cultured pearl is a completely different gem to a natural pearl and should never be compared. Out of every untouched oyster that is opened, only one in ten thousand will hold a natural pearl and only a few are found to be of gem quality enough to be used in Jewellery.

I hope this gives you an idea on how rare these gems are especially when acknowledging that the worlds production of natural pearls have nearly all dried up. The matching of a string of natural pearls is an art form all of its own, matching size, nacre and age of pearls all to make a perfect string is indeed a great challenge. When comparing natural pearls to diamonds it is easy to see how there is no comparison as diamonds are pulled out of the earth by the ton load each and every year and new finds occur on an almost daily basis, so the argument that diamonds are very rare is hard to sustain. The world’s cleverest money is now filtering into natural pearls.  There is no reason for you not to buy with the right money and buy something genuinely very rare.

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