New cobalt-bearing spinel from Lukande, Tanzania
Gem-quality spinel (MgAl2O4) from Tanzania is well known in the trade for many decades. Most of these spinels are purple or pink to saturated red. Especially famous are pinkish red spinels from Mahenge, which in fact are found at the locality Epanko (or Ipanko), about 7 km south of the small township of Mahenge
Cobalt-bearing Blue Spinel from Lukande, near Mahenge, Tanzania
Cobalt-bearing Blue Spinel from Lukande, near Mahenge, Tanzania. The Journal of Gemmology, 38(5), 474–493.
Heated spinel from Tajikistan
The spinels were nearly free of any inclusions except for a few tiny colourless forsterite inclusions. In combination with trace element analyses, the origin of these spinels could be unambiguously attributed to the famous spinel mines near Kuh-i-Lal, located in the Pamir mountains in southern Tajikistan, close
Age dating of cobalt spinel
Radiometric U-Pb dating is a promising tool in gemstone testing and is used at SSEF as an advanced analytical procedure since several years. However, this method is usually only applicable when the gemstone presents sufficient traces of radiogenic elements either in its crystal structure or within a solid inclu
Blue cobalt spinel from Vietnam
by Dr. M.S. Krzemnicki, first published in Facette 21 (February 2014) In 2013, Ms. Carina Hanser from the University Freiburg im Breisgau in Germany successfully completed her bachelor thesis on cobalt-spinel from Vietnam. Under the supervision of Dr Krzemnicki, Prof de Capitani (University Basel) and Prof
Spinel from Mahenge (Tanzania) and its Heat Treatment
first published in Facette 22 (February 2016) In 2007, the discovery of a huge pinkish-red spinel crystal of 52 kg in the carstic marbles at Ipangko south of Mahenge (Tanzania) resulted in a sudden supply of spinels (up to 100 cts) of a vibrant pinkish-red colour, which immediately mesmerized the market.Ap
U–Pb Dating of Zircon and Zirconolite Inclusions in Marble-Hosted Gem-Quality Ruby and Spinel from Mogok, Myanmar
U–Pb Dating of Zircon and Zirconolite Inclusions in Marble-Hosted Gem-Quality Ruby and Spinel from Mogok, Myanmar. Published in Minerals, 2020, 10, 195. Link to article
Spinel from Mogok, Myanmar—A Detailed Inclusion Study by Raman Microspectroscopy and Scanning Electron Microscopy
Spinel from Mogok, Myanmar—A Detailed Inclusion Study by Raman Microspectroscopy and Scanning Electron Microscopy. Published in Journal of Gemmology, 2019, 36(5), 418-435.
Cobalt diffusion-treated spinel
Cobalt diffusion-treated spinel. Published in IGC Namibia 2017 Abstract Proceedings, 151-153. Author(s): M.S. Krzemnicki, H.A.O. Wang, T. Stephan, U. Henn
Spectroscopic study of Co-bearing spinel from Luc Yen (Vietnam)
Spectroscopic study of Co-bearing spinel from Luc Yen (Vietnam). Published in 2015 Swiss Geoscience Meeting Proceedings, 130. Author(s): C. Hanser