Education

The great majority of diamonds have internal features called inclusions and surface features known as blemishes.
Together, the inclusions and blemishes are called clarity characteristics. Clarity means the relative absence of inclusions and blemishes.
However, inclusions found on the inside of the diamond have more of an influence on a diamonds beauty and value.
Diamonds with no clarity characteristics and indeed very rare, so rare in fact, that one can spend a life time in the jewellery industry without ever encountering a flawless diamond.
The Gemological Institute of America developed a clarity grading system consisting of eleven clarity grades which aide the customer in understanding the value of their diamond.

The great majority of customers believe diamonds are colourless. The truth is however, truly colourless diamonds are rare. Diamonds come in many different colours, including, yellow, blue brown, black and pink. The bigger the diamond the more obvious it's colour becomes and subtle differences in colour can add up to big differences in the price.
Most diamonds available today have subtle shades of yellow and brown. Even the slightest hint of colour can affect a diamonds overall value. That is why the Gemological Institute of America developed a colour grading scale to aid jewellery professionals properly grade diamond colour. The scale describes the normal colour from D (menaing colourless) to Z(strong yellow or brown). The letters in the scale do not describe the actual colour of a diamond. They measure how evident colour is.

Today diamonds are available in all kinds of shapes and cuts. It's important for consumers to understand what happens when light hits of fashioned diamond. Cut is very important to a diamonds overall value. A finished diamonds proportions affect the way it reflects light, a very important component in the diamonds beauty and appeal.
If light enters through the diamonds crown (the top) of a baby cut diamond, the light will exit through the pavilion (bottom) of the diamond. The diamond will appear dull and unattractive. Proportionately cut diamond will reflect most of the light through the top of the diamonds, making it bright, fiery and sparkling.
By far the most popular cutting style for a diamond in retail stores is the round brilliant cut. The term "brilliant cut" refers to diamonds that have triangular or kite shaped facets. Diamonds cut in shapes other than round are called fancy cut diamonds. Fancy cuts have their own names, such as marquise, princess, pear oval and heart.

Diamond prices depend on a variety of factors, (the 4C's), weight is just one of them. It's not always easy for a customer to understand why it is a 1.00ct diamond is worth approximately $7,000 while a 2.00ct stone of similar quality is worth $16,000.
It is really simple to understand why larger diamonds cost more, large diamonds are much more rare.
Diamond weights are stated in metric carats, abbreviated 'cts.' The metric carat can be divided into points. A point is abbreviated 'pt' and is one hundredth of a carat. A very simple way to remember the difference between the two is to think of carats as dollars and points as pennies. A $1.65 means one dollar and 65 cents, and 1.65cts can be written as one carat and 65 points.
Diamonds over one carat are expressed in carats and decimals. A 1.07ct diamond is stated as one carat oh seven. Diamonds weighing less than a carat are stated in points. A diamond that weighs .67cts is expressed as sixty-seven points.
Just like the colour grading system the G.I.A developed the metric carat in the 20th century as a step to standardize and simplify the diamond market.

It's no surprise why ruby is one of the most desired and important gemstones. After all, red is the colour of very intense emotions like love, anger and excitement. Ruby is the most valuable and popular variety of the gem species corundum. Rubies can command the highest per-carat price of any of the BIG 3 gemstones, making ruby the most important coloured gemstone in the market.
A ruby's value is determined first off all by it's colour. Clarity and size are also important, but all things being equal colour is the most important factor affecting a ruby's value. Ruby hues or colour range from orangy red to purplish red. The highest quality ruby has a pure, vibrant red to slightly purplish red colour with vivid saturation. As the colour becomes more orange purplish the value of the ruby diminishes. In it's pure form corundum is colourless. Elements known as trace elements become entangled in the gemstone and with the heat generated inside the earths crust they cause the colour of the gemstone to change. The trace elements chromium is responsible for ruby's valuable and vivid red colour. The more chromium is present in corundum the stronger the red hue becomes.

CUT:
The majority of rubies found on the market today are oval and cushion cut with brilliant cut crowns and step cut pavilions. Because it's difficult to find good quality rough corundum which can be fashioned into gemstones, cutters attempt to conserve as much weight as possible. Sometimes cutters even sacrifice colour to get as large a stone as possible.

CLARITY:
As mentioned above discovering inclusion free ruby rough in nature in nearly impossible. So it's well established rubies will have some inclusions. Not all inclusions however have a negative affect on a ruby. For example, they can aid in the separation between a genuine or synthetic ruby. Also, the presence of inclusions known as rutile silk cause light to scatter across the top of the ruby, spreading the colour move evenly, making an otherwise dark ruby appear lighter and increasing it's value. Rubies mined from Myanmar often display this rare feature. If a large and visible inclusion is located directly on near the table (top of ruby) it greatly diminished the value of the stone.

Ruby Sources: Thailand is the world's largest and most important ruby marketing centre, exporting the majority of the faceted commercial quality rubies. Myanmar (formally Burma) however hold the distinction of being the world's most important ruby source. The finest quality rubies used to create some of the most stunning jewellery pieces originate from Myanmar.

People have admired emerald's lush green colour for centuries. There are other green gemstones like tourmaline and peridot, but emerald is the most sought after green gemstone on the market. Emerald is a variety of beryl, a gem species that also includes aquamarine. An emerald's hue, tone, and saturation determine it's overall value. Even slight differences in the colour can greatly reduce or increase an emerald's value. The most desirable emeralds are bluish green to green, with strong to vivid saturation and medium-dark tone. As well, the most valuable emeralds are highly transparent.

COLOUR:
As with rubies and blue sapphires, emeralds acquire their colour due to one or more elements known as trace elements that become incorporated into the crystals structure Chromium, vanadium and iron are the trace elements responsible for emeralds lush green colour.

CUT:
Unlike most other gemstones emeralds form in a regular and uniform manner with no significant cleavages, this makes emerald rough easier to fashion. The most common cut for emeralds is the Emerald cut. This cut is ideal to show-off an emerald's lush green colour. The Emerald cut is a type of step-cut with a large square or rectangular table and faceted corners.

CLARITY:
Almost all emeralds have some inclusions that are eye-visible. Discovering eye clean or inclusion free emeralds is very rare, making relatively inclusion free emeralds extreme valuauble. Often times emerald inclusions appear mossy or garden-like, for this reason people in the jewellery trade use the French work 'jardin' (meaning garden) to describe emeralds which posses this feature.

Emerald sources and market: Columbia, Zambia, Zimbabwe and Brazil account for the great majority of the emeralds on the market today. However, emeralds from Columbia have historically been of the highest quality and the Columbian mines produce the highest volume. In fact, all other emeralds are judged against Columbian emeralds. Brazilian emeralds can also command high prices, but they generally have a bluer hue so their value diminishes when compared to Columbian emeralds. No where is demand higher for emeralds than in the US. The United States along with Japan account for 75% of the worldwide sales.

Blue sapphires belong to the mineral species corundum, the same mineral species as rubies. Corundum emcompasses all colours of the rainbow; blue sapphire is the most valuable of the sapphire variety. When the word sapphire is used alone it usually refers to the blue variety of corundum.

COLOUR:
The most important factor influencing a sapphire value in it's colour. The most highly valued sapphires are velvety blue to violetish blue, with medium to medium dark tones with strong to vivid saturation. In it's purest form, corundum is colourless. As with rubies and emeralds, sapphires contain elements called trace elements which give sapphires their vibrant blue hue. When the trace elements iron and titanium become encompassed in the gemstone, sapphire turns blue.

CUT & CLARITY:
The great majority of fashioned diamonds found on the market are oval and cushion cut, with brilliant-cut crowns and step-cut pavilions. As with rubies and emeralds it's very difficult to discover inclusion free rough sapphires. It's expected that most sapphires will contain some eye visible inclusions. Generally however sapphires have better clarity than rubies.

SCOURCES: Most sapphire deposits are located in Asia, Kashmir, Myammar, Sri Lanka, Thailand and Cambodia all have sapphite deposits. However, beauty and rarity of Kashmir sapphired is unmatched, making them the most desired and valued sapphires on the market. Sri Lanka is known for producing the largest sapphires ever mined. Thailand is the major center of sapphire trade, exporting the vast majority of gems into the market.