New Violet Orbicular Chalcedony from Ethiopia
At the GJX show, the author encountered a relatively new find of violet chalcedony reportedly discovered in Ethiopia in 2019 (figure 1). Processed and brought to market as tumble-polished freeforms, the chalcedony was offered by Orbit Ethiopia Plc. According to managing director Tewodros Sintayehu, the mine is located in the Gamo Zone region, approximately 600 km from Addis Ababa. The material was first discovered in the Gerese District and has since been found in the adjacent districts of Kamba and Garda Marta. Sintayehu noted that he had a very large quantity of the material stockpiled.
The notable features of this material were its fairly vivid violet color as well as the multitude of white orbicular structures distributed across the surface of the gems (figure 2). Microscopic examination revealed that the white color was related to a distinct botryoidal structure where a shallow outer layer of the gems contained all of the white areas. Because the white orbs are confined to a shallow surface layer, this explains why the material was sold as tumble-polished nuggets: Cutting the material into cabochons would likely result in the loss of the white orbicular pattern. A few unidentified mineral inclusions were also observed with the microscope, but the cause of the outer layer’s white orb pattern remains unclear.
This new material is quite remarkable for its beautiful pattern. Even if it is only made available as freeform tumble-polished stones, it will be a welcome addition to the chalcedony market.
