Isle of Mull

Almost every porcelain cup and furnace brick in the world is held together by needles of a mineral named after a Hebridean island.

Norman Bowen, Joseph Greig and Emanuel Zies described mullite in 1924 from Nuns Pass at Carsaig on the Isle of Mull, where Tertiary basalt had melted the sedimentary rock it intruded. The natural mineral is rare, but mullite forms whenever clay is fired hot enough, which makes it the backbone phase of porcelain and refractory ceramics. Most of the world's mullite is therefore manufactured rather than mined.