PROVENANCE OF GEMSTONES: CURRENT STATUS AND THE FUTURE (Invited Presentation)

The price of a gemstone is determined by various factors including its color, clarity, weight, and its provenance. In addition, the provenance of gemstones can be important for other study areas such as archaeology. The ability to determine where a gemstone came from can contribute greatly to our understanding of the spreading of culture and the scale of commerce in ancient times.

Since the 1960s gemologists have been focusing on studying the provenance of a specific gemstone by using various methods. Gemstones, especially those faceted are specifically hard to determine their countries of origin due to the lack of surrounding rock information; therefore, studying the inclusions is closest to directly studying the nature of their host rocks. Nowadays, gemologists still study the internal features of a faceted gemstone such as its inclusions, distribution of color zones and interfacial angles, etc. to get a rough idea of the host rocks. Later, as the geochemical technologies such as XRF as well as laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), gemologists began to understand that these new technologies provided a new window into the origin of gemstones by analyzing the trace elements incorporated into the gemstones during their growth processes. Recently, many researchers started to apply statistical analysis and machine learning algorithms to quantitatively determine the provenance of gemstones. This paper will briefly review history of the study of gem provenance, its status, and, perhaps, predict some possible future directions.