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.
It occurs as bright, sky-blue, tabular crystals (occasionally showing a square outline) embedded in hydrocerussite or cerussite, and as dull, sky-blue, granular aggregates of minute crystals in close association with chloroxiphite, probably having resulted from its alteration.
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.
In November of 1898, the British Museum (Natural History), London, acquired a few small specimens (including specimens of chloroxiphite) from the collection of Spencer Perceval by way of the London mineral dealer J.
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 (?), together with calcite, hematite, pyrolusite ("wad") and "limonite." The original collection had no catalog, and many of the specimens are without labels.
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) Only a few of the above specimens are on display.