No CrossRef data available.
Published online by Cambridge University Press: 14 March 2018
The specimen to which the following note refers was found in the Oxford Collection, and nothing is known of its origin.
It is a polished piece of translucent emerald-green stone, with patches of darker green and also patches of a dull brown colour.
The stone has taken a high polish, and brilliant internal reflections from immediately below the surface of the paler portions give it in those parts almost the appearance of a flawed emerald. But the fractured surface shows it to be merely a massive, pale green, micaceous mineral with brown patches, which appear at first sight to be only an iron-stained variety of the same substance.
1 ‘Historla Naturalis,’ Liber XXXVII, 18.