Published online by Cambridge University Press: 14 March 2018
In working on the isomorphism of Tourmaline I have been struck by the very peculiar development of a fine crystal from Pierrepont, New York, now in the Cambridge Collection.
The crystal is doubly terminated, of a jet-black colour and splendid lustre. It weighs 814.88 grammes, and measures 1⅙ inch by 1 inch by ½ inch.