Seminář: Occurrences & gemmological description of tourmaline and most important gemstone deposits of East Africa

Čas	07.05.2022   09:00 až 08.05.2022   17:00
Přidat událost do kalendáře	Google vKalendář (Windows, Linux) iCal (Mac OS X)

SGA  pořádá víkendový seminář "Occurrences & gemmological description of tourmaline and most important gemstone deposits of East Africa".

KDY: 7.- 8.5. 2022  od 9:00 do 17:00
KDE: Albertov 6, Praha 2

uzávěrka rezervací a platba do 17, dubna 2022

email registration: stepan.jaromersky@natur.cuni.cz

vstupní poplatek - členové SGA: 5 € (125 Kč) - Ostatní: 12 € (300 Kč)

HARMONOGRAM

 The lecture will last from 9:00 to 17:00

- Beginning on Saturday 7 of May – 9:00

- 10:30 – 11:00 coffee break

- 12:30 – 13:45 lunch break

- 14:30 – 15:00 snack break

- Second half beginning on Sunday 8 of May – 9:00

- 10:30 – 11:00 coffee break

- 12:30 – 13:45 lunch break

- 14:30 – 15:00 snack break 

LECTURES:

First day

Tourmaline as a gemstone – a gemmological overview with special emphasis on Paraiba tourmaline The tourmaline group is one of the most important groups of gemstones. The talk will give an overview of the geological formation of the very significant tourmaline occurrences, with special emphasis on the formation of the rarest variety – Paraiba tourmaline. Furthermore, the speaker will give an overview of the characteristics of the tourmaline gemstones, their colour causes and treatments, as well as the scientific aspects of investigating tourmalines in a gemmological laboratory.

Second day

Gemstone deposits of East Africa, with special emphasis on vanadium-bearing gemstones in Tanzania The Mozambique Belt in East Africa hosts some of the most important gemstone deposits in the world. From a geological and gemmological point of view, the regions between Tanzania and Kenya, especially the Merelani Hills in Tanzania, are very interesting. Due to a unique enrichment of vanadium, this region produces some gemstones found exclusively here – for example, tanzanites, the violetish blue variety of the mineral zoisite. This second talk will give an overview of the geological formation of the East African gemstone deposits, with a special focus on the vanadium-bearing gemstones from the Merelani Hills, their characteristics, treatments, and scientific aspects of their investigation in gemmological laboratories.

DR. TOM STEPHAN MAIN SPEAKER

Dr. Tom Stephan is the vice-director of the German Gemmological Association in Europe's gemstone capital Idar-Oberstein. He studied geosciences at the Johannes Gutenberg-University in Mainz, Germany and wrote his Master's thesis about rubies from East Africa. In his Ph.D. thesis he worked on the mathematical description (spectral fitting) of UV/Vis/NIR-spectra to calculate the colour of rubies & emeralds. At the German Gemmological Association, he works as an instructor and researcher gemmologist.