VIKING TECHNOLOGY—SUNSTONES.

VIKING TECHNOLOGY—SUNSTONES. This wikipedia article cites written records and inventories in medieval Iceland (1200 to 1500) which refer to sunstones, which one Icelandic source from the period says could be used to locate the sun even in a completely overcast sky. Danish archaeologist Thorkild Ramskou suggested in the 1960’s that the sunstone could have been one of the minerals that polarize light and had also hypothesized that the sunstone could have aided navigation in the open sea in the Viking period. The article says: “Research in 2011 …confirmed that one can identify the direction of the sun to within a few degrees in both cloudy and twilight conditions using the sunstone and the naked eye.” This article in the Economist has a photo of what has now been identified as a sunstone which was used in navigation. It was found in an English warship that was sunk in 1592, and “it was discovered within a metre of a pair of navigational dividers of the sort used to measure distances on charts.”