Paper, 'Of the mineral called by Dr Merrett Zaffora: A paper found amongst Dr [Robert] Hooke's by Mr Waller' Discusses a stone called cobalt (here 'Kobalt') which was dug out of the earth by miners. Then describes a baking process which calcifies the cobalt, which is then mixed with other minerals and becomes hard again. It is then sold and is called zoffloer or zaffora by miners. Subject: Mineralogy, Chemistry 17th century