Determining the value of a sapphire is a fairly nuanced process that considers many aspects of the sapphire. The price of any gemstone, especially a rare gem, ranges a huge amount depending on a number of factors. Sapphires can come as cheap as £25 per carat to over £11,000 per carat. Today, we’re going to take a look at those factors and questions you’ll need answers to before buying a gemstone, especially in regards to sapphires.
Emerald Cut Sapphire
What is the Genesis (Natural or Synthetic)?
While the only real difference between natural and synthetic sapphires are their origin, this difference can greatly affect price. Lab-created synthetic sapphires have the same physical properties, visual characteristics, and hardness level as the natural gemstones. They are created in a carefully controlled environment and can be made in abundance, while natural sapphires are rarer. As a result, synthetic sapphires are substantially less expensive.
What is the Treatment Status?
Treatments are processes that gemstones undergo to enhance colour, clarity, hardness, or other qualities of the gemstone. Most commercial-grade sapphires have had some sort of treatment to enhance colour or clarity. This is usually done using heat treatments, which improves colour, clarity, and removes colour zoning.
Additionally cavities and fractures within the stone can be filled with a chemical flux to improve clarity, lustre, and durability. This process can make a low value, poor quality sapphire marketable. Flux has earned a bad reputation because, in some circumstances, it is used to hold together poor quality gems, that are then sold at high prices. It is always important to be aware of treatments so this doesn’t happen to you.
What is the Colour Desirability?
Colour is said to have the greatest effect on a sapphire’s value. Most people prefer those with a strong to vivid saturation. Sapphires can come in a range of colours, with colours other than blue being known as fancy sapphires. When it comes to sapphires, however, the most valuable are those with a deep blue hue. Kashmir sapphires are particularly valued as they are superb specimens of the royal blue colour.
However, there are exceptions to this. colour changing sapphires, those that change colour under different light, may also have a high value. The typical colour-change sapphires range from blue to violet. Some very rare ones change from green to reddish brown. The colour-change quality will be graded as weak, moderate, or strong, and this will affect its value.
Padparadscha sapphires, unique orange pink sapphires, can also have a higher value, owing to their colour.
Padparadscha sapphire
What is the Clarity?
Clarity refers to whether there are any natural inclusions in a gemstone. Unsurprisingly, gems with fewer inclusions are more valuable, as this means that there is nothing obscuring the sapphire or diminishing its clarity. Blue sapphires with extremely high clarity are rare and very valuable. There are several types of inclusions that you might find in sapphires, such as long thin mineral inclusions called needles, also known as silk when they occur as the mineral rutile in intersecting groups. There are, however, other aspects to clarity, which include mineral crystals, partially healed breaks, colour zoning, and colour banding.
Occasionally, an inclusion can actually increase the value of a sapphire. Kashmir sapphires are valued not only for their colour but for the tiny inclusions many of them have, which give them a velvety appearance. These inclusions scatter light rather than impeding it, causing the coveted visual effect without negatively affecting the gem’s transparency.
Star sapphire
What is Star Corundum?
Sapphires are a variety of the mineral corundum, and star corundum exhibits a star pattern, due to oriented microscopic inclusions. Usually, the asterism effects transparency and colour, so it is quite rare to find one that exhibits transparency, depth of colour, and an asterism. As such, the value of these gemstones is incredibly high. Star sapphire refers to all colours of star corundum except red, which is called star ruby.
What is the Cut?
The cut is what makes the gem really sparkle. The initial shape of the rough sapphire crystal will always influence what shape the cutter decides to cut the sapphire to. Rough sapphires’ most common crystal form is a barrel shaped hexagonal pyramid. In order to achieve a good overall colour, maintain the best proportions, and retain the carat weight as much as possible, cutters focus on factors like colour zoning and inclusions to best determine how to orient the gem during cutting.
Colour zoning refers to areas of different colours in a stone and is a common characteristic of sapphires. Blue sapphires sometimes have colour concentrated in particular areas of the crystal. If a cutter can orient the culet – the tip of the cut gemstone – with the area of colour, the stone will appear entirely blue in the face-up position.
In general, a well-cut sapphire will be symmetrical and reflect light at the proper angles in order to enhance the stone’s lustre. A more symmetrical gemstone with the proper proportions appropriate to the chosen cut will be of higher value.
Symmetry – This is important to the overall appearance of the stone. A stone that is lopsided obviously isn’t very pleasing to the eye.
Window or Fisheye – This is when a gem has been cut too shallow and the light is escaping the stone instead of being reflected back.
Offset Culet – This is part of symmetry, but is quite significant. The culet, as mentioned is the pointed part as the bottom of the stone. If it is not perfectly centred then it may create a window, depending on how it is viewed. Occasionally, it is practice to offset the culet if there is an inclusion that can be removed by doing so.
Pear cut sapphire
What is the Carat?
Loose sapphires are often priced by the quality of the stone i.e. the other factors listed here, multiplied by the carat weight. The carat is the weight of the stone and one carat is equal to 0.2 grams. Carat affects price a great deal because, not only are larger sapphires quite rare, but the larger they get, the more often they have inclusions. Therefore, carat is often affected by clarity, which means that prices will jump a great deal from carat to carat.
What is Sapphire Grading
You may have heard of standardised diamond grading, however, grading is not something that has been established on a uniform basis within the trade for sapphires. The reason for this is that there are too many unique variables and subjective gradings within the realm of coloured stones. Diamonds are graded on the basis of not having any colour. Coloured gemstones have multiple factors that affect colour, including tone, saturation, hue, and purity. Colour interpretation is so unique from one person to the next that it’s hard to agree on a standardised basis.
What is the Condition?
The condition is simply what it says on the tin: what shape is the sapphire in? Sapphire ranks a 9 on the mohs scale of hardness, which is quite high. However, a diamond, ranking at ten, could cause scratches that mar the surface of the sapphire. It’s important to check this hasn’t happened, especially with preowned sapphires, as blemishes will affect the value of the sapphire.
Do you know the Locality?
In most cases, the origin of the stone will not have much bearing on the price. The most common locations sapphires are found in include Sri Lanka, Madagascar, Australia, the USA, Nigeria, Thailand, Vietnam, China, Cambodia, Kneya and Tanzania. However, on rare occasions, the region a sapphire is from can affect its value a great deal. As previously mentioned, Kashmir sapphires are prized for their colour and unique inclusions, which means they tend to be valued more. Additionally, Burma is famed for its quality sapphires, and sapphires from both locations will fetch a premium simply because of where they come from.
Supply and Demand
Sapphires have always been in high demand, being a hard stone, making it a great alternative for engagement rings, and having an eye-catching colour. In the early 2010s, there was rising concern that demand would overrun supply and, as a result prices increased. Unsurprisingly, they have yet to fall, meaning that you’ll be paying more for a sapphire now than you would have been ten to fifteen years ago.
