Emerald deposit, worked in the late 19th and early 20th centuries.
Emeralds are coloured by vanadium (and minor chromium) and contain complex multiphase inclusions consisting of water, gaseous methane, halite, sylvite, calcite and a sulfide assemblage (pyrrhotite, galena, and sphalerite) (Rondeau et al., 2007).
References:
- Wiik, G. H. (1995): Smaragdens historie og symbolikk. STEIN 22 (3), 155-157
- Ellingsen, H.V. (2003): Bavenitt fra Byrud. STEIN 30 (2), 23
- Imfeld, P. & Weiss, S. (2006): Smaragde selbstgesammelt: Die Fundstelle Minnesund in Norwegen. LAPIS 31 (5), 32-35
- Nordrum, F.S., Raade, G. (2006): The emerald deposit at Byrud, Eidsvoll, S. Norway. Bergverksmuseets skrifter nr. 30, 9-16
- Kvamsdal, L.O., Eldjarn, K. (2006): Mineralene i smaragdgruvene ved Byrud gård, Minnesund, Norge. STEIN 33 (4), 4-20.
- Rondeau, B., Fritsch, E., Peucat, J-J., Nordrum, F.S. & Groat, L. (2007): Characterization of Emeralds from a historical deposit: Byrud (Eidsvoll), Norway. Gems & Gemology, 44, 108-122.
- Groat, L.A., Giuliani, G., Marshall, D.D., and Turner, D. (2008): Emerald deposits and occurrences: A review. Ore Geology Reviews 34, 87-112.
http://www.nags.net/Nags/english/articles_werner/emerald_mines_byrud.htm
- http://www.smaragdgruvene.no/