Tharros was an ancient city on the west coast of Sardinia. It was apparently founded by the Phoenicians, who built on top of an earlier nuraghic settlement. Tharros was first identified with Tarshish by W.W.Covey-Crump in The Journal of Theological Studies 17 (1916) (p.280-290). William F. Albright supported this view in his Yahweh and the Gods of Canaan.
While there is evidence that the Tarshish of Bible which supplied the silver referred to in Ezekiel (27.12), the majority view is that it was brought from Andalusia. However, Tharros is also a credible alternative as it had important silver mines close at hand highlighted by a town in the region named Argentiera.
Recent isotope analysis demonstrated that Solomon’s silver could have been brought from Spain or Sardinia(a).
Modern researchers, such as Federico Bardanzellu, have also opted for Tharros as Tarshish(b).