In addition to using the 4 C’s of Diamonds chart, how can you determine the value of a precious or semi-precious gemstone? What should you be on the lookout for when you purchase your next diamond, ruby, or even tsavorite? Choosing a precious stone for unique fine jewelry can be an overwhelming experience, so we’ve compiled a comprehensive list to help you through the process.
It’s a cliché, but gemstone sizes certainly do matter. In fact, the larger a single gem’s weight, the higher the price per carat. Larger stones are much rarer than smaller stones of the same value, and their prices per carat increase exponentially. This guideline is better known as Tavernier’s Law and has been more or less utilized since the 17th century French gemstone trade.
When working with colored gemstones, the actual color is a leading determinant of its value. There are three color elements to consider before applying a price tag: hue (or shades), tone, and saturation.
Some hues are considerably more valuable than others, like the classic deep green of an emerald rather than say, a yellow-green. Tone tells us if a gemstone is ‘light’ or ‘dark’ in color. Perfect gemstone tones are referred to dealers by dealers as ‘open color’. Finally, the saturation tells us how vivid the color is. Burmese rubies are known for their deep saturated pigeon’s blood color, and If untouched and untreated, are considered extremely precious.
There are multiple facets attributed to gemstone and diamond cut, but the most notable are shape, proportion, and finish.
A rough stone will often dictate the final cut, barring any large inclusions. Market preference also holds a great deal of sway. For example, a marquise-cut diamond is a far less desirable shape than a round-cut diamond and is usually holds 10-20% less value.
A well-trained cutter will find a balance between a shallow cut that allows light to pass through (a “window”), and blocking light (“extinction”). High quality work provides brilliance and clarity which are reflected back to the viewer.
This is the last step in the gem-cutting process, but finishing cannot be overlooked. Issues may include unjoined facets, poorly edged facet junctions, and leftover marks and scratches from the polishing process. Though these are often fixable, they take away from an otherwise exceptional piece.
Inclusions (flaws) in most gemstones will typically decrease clarity, and thus, their value. Fractures and cracks increase the risk of further breakage, and – in the case of diamonds – these issues distract from the stone’s beauty when they’re visible with the naked eye.
There are hundreds of ways that buyers can be tricked into purchasing a gemstone with substandard clarity. A great example is how gem specialists fill emeralds with oil to cover up imperfections.
Though it’s understandable to have these imperfections repaired with a variety of substances, inclusions do not always depreciate the value of a stone. In fact, emeralds are revered for their imperfections. Talented gem experts will incorporate these in the cutting process, as each emerald has a unique story to tell.
Though diamonds a girl’s best friend, they’re only reported as rare for advertising campaigns. Scarcer gemstones like opals, emeralds, and the unbelievably elusive benitoite can have an incredibly high value per carat. Granted, these prices often come down to market demand. For example, gem-quality peridot is a rare find, but certainly less in demand than the other birthstones!
When gem lovers think of Elizabeth Taylor, her unbelievably fabulous and eponymous colorless diamond ring quickly comes to mind. After her death in 2011, the value of her daily-worn 33.19-carat bauble was estimated to bring in $2.5-3.5 million at auction. Yet when the gavel came down at a staggering $8.8 million, few were truly shocked.
On paper, an expected price can be absolutely different from market demand. And a love story like the one between Richard Burton and Elizabeth Taylor can make a huge difference in terms of value.
Over the centuries, dynastic monarchies and marketing experts alike have stereotyped locations as sourcing the finest gemstones of their kind. For example, Ceylon sapphires have long been associated with the deepest blue gemstones, and Colombian emeralds have had a strong reputation as possessing the most beautiful green color available.
Name recognition is not the most accurate method of determining a stone’s cost though. In fact, stunning Australian and Madagascan sapphires have begun to rival those from Ceylon, just as Zambian emeralds are known for their wide range of blue, green, and yellow hues.
Is There an Easy Way to Price a Gemstone?
Determining the value of a precious or semi-precious stone is often more of an abstract concept than anything.
Unlike gold and silver – which are publicly traded commodities – the price of precious and semi-precious gemstone stocks are manipulated almost entirely by supply and demand. Even expert pricing systems like The Rapaport Price List – used by diamond traders – only take the 4Cs into account and can be considered a benchmark of sorts to determine gemstone values.
At Jaume Labro, we choose the finest gemstones with great care. Each diamond is certified by the Gemological Institute of America (GIA), and all hand-cut stones are sourced from sustainable sources. We believe in creating handcrafted mokume gane jewelry only with the finest materials available.