In this Iland is marble enough, whereof the late Earle of Argyle caused polish a piece at London abundantly beautifull. In a particular place of the Island, neer the sea ebbing and flowing thereinto, there are found transparant stones of all colours, but most ordinarily green, much resembling agatts: they yield to the file and […]
The nephrite of Iona has a specific gravity of 2.595, H 3.5, SiO3 44.85, MgO 36.05, FeO 3.6, Al2O3 1.3, HO 13.55. — Cyclopaedia of Chemistry with Its Applications to Mineralogy, Physiology, and the Arts, Robert Dundas Thomson, Griffin and Company, 1854, page 379.
A small geological outcrop at the south end of the isle of Iona is the source of a rare stone known since the time of St. Colum Cille and treasured for centuries. Iona greenstone (also called Iona marble, nephrite, jade, and a host of other more-or-less mineralogically correct names) may be found on the beach […]