In the world of colored gemstones, provenance can have a substantial impact on gemstone value – according to some estimations as high as 15 percent. Ruby, sapphire, red spinel, tourmaline, and emerald values can all be strongly impacted by their geographic origin.
This number can be even higher when especially large or rare stones are concerned, and certain regions have an exponential impact on value due to heritage and scarcity. For example, both Kashmir sapphires and Burmese rubies command top prices. This may be in part because some mines have a long history (Burmese ruby mines are a prime example) or no longer exist (like the Kashmir sapphire supply). History, legend, and scarcity can all add to the desirability of a particular gem, which in turn impacts its value.
The regions outlined below are some of the most famous regions of origin for colored gemstones. If purchasing a precious gemstone reputed to be from any of the following locations, it is always a good idea to get a laboratory report to confirm it.
The stunning color of this burmese ruby is a prime example of why rubies from this area are so highly regarded in the gem industry.
Burmese “Pigeon’s Blood” Rubies
The Mogok stone tract in Myanmar is famous for its legendary “pigeon’s blood” rubies. The history of the mines here extends centuries into the historic record. The rubies occur in a gravel layer called byon and are usually discovered somewhere between 20 to 100 feet underground. These stones are overwhelming harvested by artisanal miners who hand-wash and screen both alluvial deposits and traditionally mined stones.
Kashmir sapphires exhibit a velvety luster and intense blue coloration.
These fine, intensely blue colored stones are found in the NW Himalayas of Northern India at an elevation of nearly 15,000 feet. Due to the elevation and climate of the region, the deposit-bearing areas are covered in snow for most of the year. Because of a limited supply and aggressive mining in the 19th century, these deposits are now largely exhausted.
Montana sapphires in a range of tones.
Fine sapphires are also found in the United States. Yogo Gulch, Montana in particular produces fine blue sapphire, although sapphire crystals of almost every color are also found there. Although the stones are typically small, the blue stones are highly desired and often exhibit a unique, metallic luster.
As regions of the world like the ones above became acclaimed for specific gemstones , trade names started to be utilized to denote particular face-up appearances from specific geographic locations. The names extend across a wide array of gemstones: “Paraíba” tourmaline, “Biwa” pearl, “Colombian” emerald, “Australian” sapphire, and those listed above. Even long after locations have been depleted, the names persist.
Many in the trade are frustrated when a location is used as a typological name as opposed to truly denoting a gemstone’s source of origin. In some cases, unscrupulous dealers will go so far as to call a gem a “Kashmir” sapphire, for example, when its color mimics material from that location but the stone is not actually from the described area. These types of concerns are why a country-of -origin report from a major lab that indicates the gemstone has been tested and has the features associated with that specific country is so important.
A gem dealer carefully weighs a large emerald in Bogota, Colombia.
Some Issues with Gemstone Origin Reports and Their Reliability
Origin reports were first offered by the Gübelin laboratory in Switzerland in the 1950s. The reports were based on Dr. Edward Gübelin’s studies regarding how inclusions can help identify gem sources.
Because there were fewer overall deposits at that time, origin determination was not as complicated as it is today. For example, rubies either came from Mogok, Burma or Thailand. The two deposits exhibited substantial differences that were relatively easy to identify. There were also a few small pockets of rubies found in Ceylon, but the specimens were still distinct enough to allow separation from the other locations. Emeralds were primarily from Colombia or Russia, and while sapphires were more prolific, again distinctions between the gemstones found in areas like Sri Lanka, Australia, and Myanmar were substantial enough to allow for relatively reliable results.
Today the analysis process has changed considerably. The substantial increase in gemstone deposit discoveries of all kinds means that many now share similar geologic formation characteristics with the older mines. As a result, separation has become more complicated.
A few major grading labs have the equipment and expertise to determine geographic origin today, but that doesn’t mean that they can successfully determine the country of origin for every gemstone submitted. `While the gem trade wants lab reports to provide 100% accuracy and be consistent from report to report, in some cases this can be almost scientifically impossible to accomplish because the analyzable differences are so slight – especially for sapphires. These laboratories make their determinations by collecting spectroscopic data and identifying types of inclusions in the gem sample provided for analysis. The results are then compared to those from reference gems positively identified as originating from certain locations. If the gem shows strong correlating evidence with a specific region, it will be labeled as originating from that area on the report. However, if the data overlaps with gems from two locations or more, the report will have the result of “inconclusive.” Although it is disappointing to gem traders when an inconclusive origin is returned, until methodologies improve in some instances it may be an unavoidable part of the process.
The Future of Origin Reports
While the primary focus of origin reports has been the confirmation of monetary value for precious stones, its potential in other applications cannot be denied. As the ethics of gemstone mining and distribution have come into play, many consumers want to know the social and economic impact of the gemstones they purchase. Origin reports offer an important possible way to avoid conflict areas by pinpointing the geographic locale of the stone’s origin. Is it sustainable, is it environmentally responsible, are labor conditions safe and fair? Geographic origin determination could play a significant role in providing answers to these questions.