For centuries, it has been a crystal of legend locked in the verses of Norse myth with little or no evidence that it was ever real. Now it seems scientists at last have grounds for believing that the Viking “sunstone” used to navigate the seas did indeed exist.
Not just the stuff of legend: Famed Viking ‘sunstone’ did exist, believe scientists
cool!
Comments From The Peanut Gallery 
That is an absolutely amazing method of solar location for navigation. Very cool, thank you for sharing.