Metpetruby
Corundum-forming reaction in the Fiskenæsset complex: forsterite/serpentinite from ultramafic rocks in contact with anorthositic rocks react with cross-cutting pegmatites to form a range of new minerals, including pargasite (green) or anthophyllite (silver-brownish), spinel (red) or ruby/sapphire or sapphirine (greyish-blue), biotite and/or black amphiboles.