Sunstone Unearthed From Shipwreck – ScienceNOW
ScienceShot: Sunstone Unearthed From Shipwreck – ScienceNOW.
…That led researchers to believe these crystals, which are commonly found in Iceland and other parts of Scandinavia, might have been the powerful “sunstones” referred to in Norse legends, but they had no archaeological evidence to support their hypothesis—until now. After subjecting it to a battery of mechanical and chemical tests, the team determined that the Alderman crystal is indeed a calcite and, therefore, could have been the ship’s optical compass…
Sable Aradia, Priestess & Witch 