For hundreds of years the Vikings journeyed across the North Atlantic through clouds of fog, using superior skills of navigation. How the Vikings became prolific navigators has baffled scientists for years, but one theory suggests they used a technique involving Sunstones.
Famous Viking tales such as “The Saga of King Olaf”, mentioned Sunstones as a mysterious way in which the Vikings were able to navigate. It’s thought that the Vikings would be dependent on these Sunstones on cloudy days, or when fog rolled in and left no clear route.
The Suns position could be located by looking through one of the crystals. These Sunstones may have been used to detect polarized light, which would have enabled them to locate the Suns position, even when it wasn’t visible.
The Sunstones however were thought to be fictional, but that may not be the case after all. In 2007, a team of Hungarian researchers at Eotvos University in Budapest carried out tests on Cordierite, which was known to have been used in the Viking era, and they found the crystals to be surprisingly accurate in locating the Suns position.
An international team of researchers led by Guy Ropars of the University of Rennes in Brittany, also made the claim the legendary Viking Sunstones were not fictional. The researchers claim that the Vikings used transparent calcite crystal (also known as Icelandic Spar), to track the location of the Sun. Using calcite crystal, they were able to locate the Sun within a single degree of accuracy.
Calcite crystal is completely natural, and would work by depolarizing light, filtering and fracturing it along different axes.
Here’s how the Viking Sunstones would work:
There is also other historic evidence which proves that sailors were aware of the crystals capabilities, when it came to maritime navigation.
Calcite crystal was found onboard an Elizabethan ship which had sunk in 1592. Compasses would have been used around this time, but Calcite was probably kept on board as a backup.
Though research continues in the Viking Sunstones, the knowledge and ability of the Viking people made them incredible navigators.