Basel, Switzerland—The Swiss Gemmological Institute SSEF conducted intensive research on high-quality Afghan emeralds and has released its findings for the trade. 

In 2017, the lab started seeing a new kind of emerald from the country’s Panjshir Valley, nearly all of which were fine quality, SSEF Director Michael Krzemnicki said.

As they do for all less familiar material, researchers at SSEF decided to study the emeralds extensively to find ways to separate them from others. 

This was necessary, especially given that the material is occasionally mislabeled as Colombian, Krzemnicki said. 

The high-quality Panjshir Valley emeralds closely match the South American specimens in terms of both their appearance and their gemological properties, SSEF said.

The Swiss lab conducted the study by testing and analyzing more than 100 gem-quality emeralds from the Panjshir Valley, ranging from 1 carat to more than 30 carats. 

It also looked at emeralds from Colombia, Zambia, Ethiopia, Pakistan and Davdar, China, the lab confirmed. 

To develop reliable ways to distinguish the Afghan emeralds from others, SSEF compared emeralds from different origins through laser-ablation mass spectrometry using its state-of-the-art GemTOF instrument and by applying a machine-learning statistical algorithm for data processing and visualization.

By compiling 56 elements in the calculation, the Afghan emeralds could be characterized and differentiated from other emeralds, particularly Colombian. 

The research team reported that gemologically, Afghan emeralds are characterized by spiky to tubular fluid inclusions and very fine and parallel hollow channels, both of which are similar to inclusions that can be found in Colombian emeralds. 

But though the team also occasionally saw “chevron-like” growth features, the honeycomb-like pattern characteristic of Colombian emeralds—a graining often known in the trade as “gota de aceite”—has not yet been spotted in Afghan emeralds.