The first ever found remnant of a sunstone, a crystal which legend says was behind the Vikings’ incredible feats of oceanic navigation? Via CBS News:
A rough, whitish block recovered from an Elizabethan shipwreck may be a sunstone, the fabled crystal believed to have helped Vikings and other medieval seafarers navigate the high seas, researchers say.
In a paper published earlier this week, a Franco-British group argued that the Alderney Crystal – a chunk of Icelandic calcite found amid a 16th century wreck at the bottom of the English Channel – worked as a kind of solar compass, allowing sailors to determine the position of the sun even when it was hidden by heavy cloud or fog, or below the horizon.
Icelandic legend appears to refers to such a crystal [but] few other medieval references to sunstones have been found, and no such crystals have ever been recovered from Viking tombs or ships.