In December 1910, the Hoffell farmer, Gu�mundur J�nsson, was looking for sheep in Hoffellsdalur valley when he found a large number of Iceland spar fragments in a domed ceiling just inside the entrance of the main building of the University of Iceland, and in the altar of the University chapel.
22.
To derive a course to steer relative to the sun direction, he uses a sun-stone ( Solarsteinn ) made of Iceland spar ( optical calcite or Silfurberg ), and a " horizon-board . " The author constructed the latter from an Icelandic saga source, and describes an experiment performed to determine its accuracy.
23.
Other major resources are natural gas, coal, ferrous metal ores, manganese, chromite, iron ores, non-ferrous metals ores ( lead, tungsten ), non-metallic ores ( rock crystal, fluorite, iceland spar, sulfide pyrites, barite, silicates, silica, asbestos, talcum ), deposits of precious and semi-precious stones and natural stones ( malachite, jade, granite ).
