Paraiba or Not? Cu-bearing Tourmaline with a Distinct Fe Concentration. Published in Journal of Gemmology, 2022, 38 (1), 20-22.
Copper-bearing tourmaline from Nigeria is known in the trade since about two decades (Milisenda 2001, Henricus, 2001; Smith et al., 2001; Zang et al., 2001). The first reported material from Nigeria was rather of aquamarine- to amethyst-like colours, but shortly after it was followed by a limited and sporadic p
by Dr. M.S. Krzemnicki, first published in Facette 27 (June 2021) Tourmaline is a mineral group of complex boro-silicates and is well known to produce gemstones in a wide range of beautiful colours. A specifically attractive variety is vivid yellow elbaite tourmaline, which owes its colour to manganes
At the SSEF, origin determination of Paraiba tourmalines is based on years of experience researching collection samples from SSEF and Prof. Hänni collections, donated and loaned samples from clients, as well as knowledge from scientific literature. However, the mining area and depth of the material have been i
by Dr. M.S. Krzemnicki, first published in Facette 20 (January 2013) The Swiss Gemmological Institute SSEF recently received a necklace for testing that consisted of thirty-three slightly polished light blue to greenish-blue and purple beads. It had originally been sold as Paraiba tourmaline to our client. The
Multi-Element Correlation Analysis of Cu-bearing Tourmaline using LA-ICP-Time-Of-Flight-MS. EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16170, https://doi.org/10.5194/egusphere-egu21-16170, 2021.
In October 2017, a team of gemmologists from the SSEF had the privilege to visit some Paraiba tourmaline mines in Brazil to get impressions about mining procedures, sorting, cutting and trading activity in the states of Paraiba and Rio Grande do Norte.
Paraiba tourmaline intergrown with lepidolite mica. Published in Journal of the Gemmological Association of Hong Kong GAHK, 33, 56-58. Author(s): M.S. Krzemnicki