On corundums from Umba, Tanzania
On corundums from Umba, Tanzania. Published in Journal of Gemmology, 1987. Author(s): H.A. Haenni
Glass-like fillings in rubies and sapphires
Glass-like fillings in rubies and sapphires. Published 1986. Author(s): H.A. Haenni
Corindons traités avec obturations vitreuses
Corindons traités avec obturations vitreuses. Published 1986. Author(s): H.A. Haenni
Korunde aus dem Umba-Tal, Tansania
Korunde aus dem Umba-Tal, Tansania. Published in Zeitschrift der Deutschen Gemmologischen Gesellschaft, 1986. Author(s): H.A. Haenni
Naturally-coloured and treated yellow and orange-brown sapphires
Naturally-coloured and treated yellow and orange-brown sapphires. Published in Journal of Gemmology, 1983. Author(s): K. Schmetzer, G. Bosshart, H.A. Haenni
Naturfarbene und behandelte gelbe und orange-braune Sapphire
Naturfarbene und behandelte gelbe und orange-braune Sapphire. Published in Zeitschrift der Deutschen Gemmologischen Gesellschaft, 1982. Author(s): K. Schmetzer, G. Bosshart, H.A. Haenni