The value of high-end coloured gemstones can increase dramatically depending on their origin, making ‘country of origin’ a critical value factor alongside stone quality factors such as colour, size and shape. What does it take to make accurate, reliable origin determinations?
Comprehensive sample collections
GIA’s field gemologists travel the world examining mines and collecting samples for GIA’s unrivalled gemstone reference collection. With 26,002 coloured gemstone samples and counting, including corundum, emeralds, spinels, alexandrites and more, GIA’s reference collection continues to grow. These gemstones are meticulously documented and researched. As databases expand and more information is gathered, previously held beliefs about criteria for geographic origin may change. For example, the assumption that orange fluorescence in blue sapphires was unique to Sri Lanka was debunked when GIA researchers discovered its presence in several low-iron metamorphic deposits.
Advanced scientific instruments
Advanced instrumentation is essential for laboratories issuing geological reports. As these instruments become more sophisticated, more expertise is required to operate them. This is particularly true for certain chemical analysis techniques, such as laser ablation. The cost of such equipment may be prohibitive for smaller laboratories, but GIA laboratories use the most advanced microscopes and spectroscopy instruments to ensure accurate determinations.
Geography versus Geology
Interesting fact: Did you know that gemstone deposits are determined by geology, not geography? Country borders don’t affect where gems are formed, and gems from different deposits can have similar characteristics. For example, some blue sapphires from Myanmar are virtually indistinguishable from those from Sri Lanka. Understanding these technicalities is essential for accurate gemstone valuation.
Continuing education opportunities with the GIA Alumni Collective
The GIA Alumni Collective’s ruby, sapphire and emerald country of origin seminars offer professionals the opportunity to learn from field researchers dedicated to these studies. The seminars introduce topics such as global coloured gemstone deposits, advanced analytical techniques, and building a reference collection of origin. Interactive sessions, live demonstrations and digital reference materials provide an engaging and comprehensive learning experience, including fascinating case studies.
Understanding the complexities of country of origin determination is a challenging yet critical aspect of the gemstone trade. By attending these comprehensive seminars, delegates will gain critical insight into the value and provenance of gemstones, enabling them to make more informed decisions in this rapidly evolving industry.
