T he pricing laws of blue sapphires are similar to the pricing laws of other many other gem types. The cardinal rule to remember when evaluating all gems is that a small difference in looks can mean a large change in price.
One of the biggest hurdles to the gemstone industry is understanding the mechanics of pricing. Unlike the diamond industry, the colored gem industry does not have standardized colors and clarity grades. As a result, no colored gem price list exists that can really help you understand how pricing works.
Much of the mystery in blue sapphire-pricing results from the color shades found on the market. It is often recognized that color is the single most important factor when evaluating sapphires. Some blue colors are more desirable than others, and as a result the market is willing to pay many times more for them.
What may seem to the untrained eye as a minor change in color often gives us dramatic changes in price. A small shift from a pale light blue towards a deep cornflower blue gives a large jump in the value of a sapphire’s per carat price. As if the high values are balancing precariously on a razor-edge, a move away from these deep cornflower blues towards the darker midnight-blues, causes a quick and spectacular crash in price that can mean thousands of dollars when dealing with larger sapphires.
As the weight of a sapphire increases, so does its per carat price. Big sapphires are rarer than smaller ones and the market is willing to pay higher per carat prices to get them. Consequently, the value of a 3 Carat sapphire is far more than that of three 1 Carat sapphires of a similar quality.
The following graph is an attempt to bring some kind of visual understanding of how both color and weight affect sapphire prices. It is based on sapphires of perfectly equal clarities, cuts, and enhancements. However, please remember that it is a graph of sapphire color and weight pricing theory only. It should not be used as a price guide.
Not seen in the graph is the “per carat price increase ceiling” experienced when sapphires go above the 15-20 Carat weight mark. Per carat price-jumps slow dramatically as sapphires become too large for use in regular jewelry. Often such large specimens are bought by collectors of rare gems, remaining loose, unset in jewelry.
In the everyday rough and tumble of the sapphire markets, other pricing factors need to be look at, such as good cutting, lack of undesirable color overtones, clarity, origin, and enhancements. Once accounted for, the way that sapphire carat prices rise and fall in relation to their color and size remains constant.