The mine is the type locality for the minerals chloroxiphite and diaboleite, and has also produced some of the largest known crystals of hydrocerussite and crednerite.
Now is therefore an appropriate time, 100 years after it was last worked, to look back at the history, geology and mineralogy of this interesting locality where the minerals chloroxiphite and diaboleite were first discovered.
Higher Pitts mine chloroxiphite was described as a new species by Spencer and Mountain in 1923.
Dull aggregates and films of minute crystals may cover areas up to about 5 x 30 mm in association with chloroxiphite.
Leonard James Spencer (1870-1959), the discoverer of chloroxiphite and diaboleite, joined the British Museum (Natural History), London, as an assistant in the Department of Mineralogy in 1894.
Spencer published the results of his investigations in 1923 and, together with Edgar Donald Mountain of the British Museum (Natural History), London, who had performed the chemical analyses, described the new minerals chloroxiphite and diaboleite (Smith, 1982; Spencer and Mountain, 1923).
It is of interest to note that the famous American collector Washington Augustus Roebling (1837-1926) had acquired specimens of mendipite, chloroxiphite, diaboleite and crednerite from the Higher Pitts mine as early as 1894 (in London from the German mineral dealer Oscar Penzig).
The remainder of the specimens from the Higher Pitts mine consists of one or more of the following minerals: cerussite, hydrocerussite, mendipite, crednerite, malachite, chloroxiphite, diaboleite, mimetite and wulfenite (?
Specimen Size (cm) Minerals 001-048 [less than]5 Loose masses of cerussite crystals 049-055 - Hydrocerussite, cerussite, "wad" 056-060 [less than]5 Mendipite 061-067 [less than]5 Mendipite, chloroxiphite, diaboleite 068 [less than]5 Mendipite, chloroxiphite, diaboleite 069 [less than]5 Mendipite 070-074 - Hydrocerussite 075-076 - Cerussite 077-078 - Cerussite 079 - Cerussite 080 - Cerussite 081-083 [less than]5 Mendipite 084 [less than]5 Mendipite 085 - Cerussite 086 - Crednerite, diaboleite 087-092 [less than]5 Mendipite, chloroxiphite, diaboleite 093 - Cerussite 094-098 - Cerussite 099-101 [less than]5 Mendipite 102-103 - Cerussite 104 - "Wad" 105 - Cerussite 106 [less than]5 Mendipite 107 - Crednerite 108 - Crednerite (very fine)
The distribution of the various minerals agrees with the observations of Spencer and Kingsbury: groups of cerussite crystals and nodules of hydrocerussite were much more common than nodules of mendipite, and only a small number of the nodules of mendipite contained chloroxiphite or diaboleite, with diaboleite being much rarer than chloroxiphite.
Arthur Kingsbury's collection contained a fine set of specimens from the Higher Pitts mine, including the best known specimens of wulfenite and crednerite and some of the best known specimens of mendipite and chloroxiphite.