Date: 16:00 – 18:00, Friday, July 31, 2020
日時: 2020年7月31日（金）16:00 – 18:00
Speaker: Ahmadjan Abduriyim (Tokyo Gem Science LLC, GSTV Gemological Laboratory)
Title: UPDATE OF WORLDWIDE GEMSTONE DISCOVERY AND MINING ACTIVITIES AFTER 2000
The gem market highly rates certain gemstones with a premium price when they originate from reputable sources (gem deposits). As a consequence, this increases the need for gem testing services by major gemological laboratories with a focus on geographic origin determination. In the past few decades, several new deposits of rubies and sapphires have been discovered in East African countries such as Tanzania, Mozambique, and Madagascar. Sapphires also came from Sri Lanka. Recently, several gemstone mines have been significantly developed by using high tech machineries, but many others are still worked using simple basic tools and techniques by local miners. To provide and collect information from current active gemstone mining countries, the author visited several well-known gem deposits in different countries to report their new discoveries and current mining activities. This aimed to update data on major gemstones which are usually focused on for their geographic origin determination, using the collected optical and chemical data for reference.
Specially, the author will introduce the following reviews from this online seminar.
1) A review of geology of corundum and emerald gem deposits.
2) Update the discovery and understanding the development and gem deposits.
3) Introduce the analytical methods used in geographic origin determination of gemstones.