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New lead-copper minerals from the Mendip Hills (Somerset)

Published online by Cambridge University Press:  14 March 2018

L. J. Spencer
L. J. Spencer*
Affiliation:
Mineral Department of the British Museum (Natural History)
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Extract

Although mining operations have been carried on in the Mendip Hills for a period of about 2000 years—probably since pre-Roman times, very little is known respecting the minerals that occur in the district. The reason for this is that most of the mines were exhausted previous to the development of mineralogy as an exact science; and furthermore only few specimens have been preserved in collections. During the nineteenth century operations were mainly confined to re-working the vast accumulations of refuse left by the earlier miners. This work was continued at the St. Cuthbert's Lead Works (1 mile ESE. of Priddy) up to the year 1908, since when all work has ceased on the Hill. The latest mining was for iron and manganese ores at Higher Pitts farm (1 mile SSE. of Priddy); here work ceased in 1893.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 20 , Issue 102 , September 1923 , pp. 67 - 92
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1923

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References

Page 68 note 1 John Woodward (1665-1728), An attempt towards a natural history of the fossils of England ; in a catalogue of the English fossils in the collection of J. Woodward, M.D. London tome I, 1729 ; tome II, 1728.

Page 68 note 2 John Woodward's collection of ‘Bodyes digg'd up out of the Bowels of the Earth’ has been carefully preserved in its original state in the old cabinets. Being one of the oldest collections of minerals (and fossils) now extant [ef. Min. Abstr., vol. 2, p. 7], it is of great historical interest. But, in addition, it contains much valuable information respecting forgotten occurrences of British (and foreign) minerals. The localities and conditions under which each specimen was found were recorded with greater care than is often the case at the present day ; and the specimens were catalogued, numbered, and arranged most methodically.

Page 69 note 1 Woodward, H. B., List of Minerals found in Somersetshire. Geol. Mag., 1872, vol. 9, p. 129 CrossRefGoogle Scholar ; Geology of east Somerset and the Bristol coal-fields (Mem. Geol. Survey), 1876, pp. 176-177.

Page 69 note 2 Rudler, F. W., Handbook… Minerals of the British Islands… Iuseum of Practical Geology, London 1905, pp. 107–112 Google Scholar.

Page 69 note 3 Spencer, L. J., Leadhillite in ancient lead slags from the Mendip Hills. Rep. Brit. Assoc., 1899, for 1898 (Bristol), p. 875 Google Scholar ; Geol. Mag., 1899, pp. 71-72.

Page 69 note 4 A good account of the history of mining in the Mendips is given by Hunt, R., ‘British Mining’, London, 1884, pp. 31, 131, 230Google Scholar. McMurtrie, J., Notes on the forest of Mendip, its mining customs and ancient laws. Trans. Inst. Mining Engin., 1902, vol. 20 (for 1900-1901), pp. 528–582 Google Scholar. T. Morgan, Notes on the lead-industry of the Iendip Hills. Ibid. pp. 478-493.

Page 69 note 5 A few smaller specimens from tile S. G. Perceval collection were acquired by purchase through Mr. J. R. Gregory at the end of 1898.

Page 69 note 6 My thanks are due to Mr. A. E. Culliford, the present owner of Higher Pitts farm.

Page 70 note 1 The official mining returns published by the Home Office for the years 1890 and 1891 give for manganese-ore from Higher Pitts mine 30 tons and 50 ions respectively.

Page 70 note 2 This is referred to by H. B. Woodward in Mem. Geol. Survey, East Somerset, 1876, p. 175, but I have been unable to trace the original source of the information. On p. 171 he quotes early assays of the argentiferous galena from this locality.

Page 71 note 1 See Campbell Smith, W., Min. Mag., 1913, vol. 16, p. 337 CrossRefGoogle Scholar. As here mentioned, one of the specimens is entered in the Pennant MS. catalogue as coming from ‘Galway’.

Page 71 note 2 Berzelius, J. J., K. Vetenskaps-Acad. Handl., Stockholm, 1824, for 1823, p. 184 Google Scholar ; German translation in Ann. Phys. Chem. (Poggendorff), 1824: vol. 1, p. 272 ; English abstract in Annals of Philosophy, 1824, vol. 24 (n. ser. vol. 8), pp. 154-155.

Page 71 note 3 Edinburgh Journ. Sci., 1824: vol. 1, p. 379.

Page 71 note 4 Lévy, A., Annals of Philosophy, 1824, vol. 24 (n. ser., vol. 8), p. 243 Google Scholar ; Description d'une Collection de Minéraux, 1837, vol. 2, p. 448.

Page 71 note 5 Rhodius, R., Ann. Chem. Pharm., 1847, vol. 62, p. 373 CrossRefGoogle Scholar. Sehnabel, C., Ann. Phys. Chem. (Peggendorff), 1847, vol. 71, p. 516 CrossRefGoogle Scholar.

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Page 71 note 7 Ditte, A., Compt. Rend. Acad. Sci. Paris, 1882, vol. 94, p. 1180 Google Scholar.

Page 72 note 1 This occurrence was briefly mentioned by H. B. Woodward, Prec. Geol. Assoc. London, 1890 vol. 11 p. cxcviii and by F. W. Rudler in 1905 (loc cit., p. 109).

Page 72 note 2 Now Harptree, on the north side of the Mendips. On Smitham Hill, above East Harptree, I have recently picked up bits of galena, smithsonite, wad, limonite, barytes calcite, &c., from the rabbit burrows in the old waste heaps.

Page 72 note 3 The two mendipite specimens from Harptree in the Woodwardian collection at Cambridge Show a more pronounced divergent grouping and in one of them the prisms radiate in all directions from a central point in the nodule.

Page 73 note 1 Previously determined values of the cleavage-angle of mendipite are by J. J. Berzelius (in 1824), 77 1/2° ; W. Haidinger (1824), 77° 33' ; A. Lévy (1824), 77° 35'; A. Breithaupt (1832), 77° 80'; W. H. Miller (1852), 77° 24'; and L. Fletcher (Min. Mag., 1889, vol. 8, p. 178), 77° 19'.

Page 73 note 2 E. S. Larsen (Bull. U.S. Geol. Survey, 1921, no. 679 p. 108) gives for mendipite from Brilon, Weslphalia, the optic sign as positive, 2V nearly 90° and refractive indices α 2.24, β 2.27;, γ 2.31.

Page 78 note 1 Possibly some of these blue stains are azurite. But the only azurite that I have seen from Higher Pitts is a very small piece in the collection of Mr. William H. Janes, of Wookey Hole, which was examined in the hope that it might be the new blue mineral. It shows crystalline particles embedded in a paler earthy material. Associated with it arc malachite and limonite.

Page 79 note 1 Fór the latest work on boleite, see A. Hadding, 1919. [Min. Abstr., vol. 1, p. 76.]

Page 80 note 1 The two specimens from Leadhills (a locality not mentioned in the literature for hydrocerussite) were purchased for the collection in 1861 as ‘aurichalcite’.

Page 80 note 2 Nordenskiöld, A. E., Nya mineralier från Långban. Geol. För. Förh. Stockholm 1877, vol. 3, p. 381 CrossRefGoogle Scholar.

Page 80 note 3 Lacroix, A., Sur un hydroearbonate de plomb (hydrocérussite) de Wanloekhead (Écosse). Bull. Soc. Min. France, 1885, vol. 8, pp. 35–36 Google Scholar.

Page 81 note 1 Lacroix, A., Les minéraux néogènes des scories plombeuses athéniennes du Laurium (Grèce). Compt. Rend. Acad. Sci. Paris, 1896, vol. 123, pp. 955–958 Google Scholar. Lacroix, A., and de Schulten, A., Bull. Soc. FranÇ Min., 1908, vol. 31, pp. 79–90 Google Scholar.

Page 81 note 2 Pilipenko, P. P., 1915, loc. cit. [Min. Abstr., vol. 2, p. 111.]Google Scholar

Page 81 note 3 Bertrand, É., Bull. Soc. Min. France, 1881, vol. 4, p. 87 Google Scholar.

Page 81 note 4 Flink, G., Bull. Geol. Inst. Univ. Upsala, 1901, vol. 5 (for 1900), pp. 94–95 Google Scholar. plate 3, figs. 11 and 12. Arkiv Kemi, Min. Geol., 1910, vol. 3, no. 85, p. 162.

Page 81 note 5 Heddle, M. F., Min. Mag., 1889, vol. 8, p. 202 Google Scholar ; Mineralogy of Scotland, 1901, vol. 1, p. 147.

Page 81 note 6 Bourgeois, L., Sur la reproduction artifieielle de l'hydrocérusite, sur la composition chimique de cette espèce minérale et sur la constitution du blanc de cruse. Bull. Soc. Franç. Min., 1889, vol. 11, pp. 221–225 Google Scholar. Preliminary note in Compt. Rend. Acad. Sci. Paris, 1886, vol. 103, p. 1090.

Page 81 note 7 Larsen, E. S., Bull. United States Geol. Survey, 1921, no. 679, p. 202 Google Scholar.

Page 82 note 1 See Campbell Smith, W., Min. Mag., 1913 vol. 16, p. 331 CrossRefGoogle Scholar. This specimen (B.M. 1913,69), presented by the Earl of Denbigh in 1913, bears the label ‘Halkin’ (Flintshire), but to judge from its general appearance and association with crednerite and green and blue copper stains it is difficult to believe that it is not from the Mendip Hills.

Page 84 note 1 This specimen was given to meat Priddy in June 1898, together with the samples of ancient lead slags in which I found crystals of leadhillite. The superficial resemblance of the material to leadhillite was at the time puzzling. It is now evident that the specimen belongs to the material that, a few years before, had been found at Higher Pitts.—L. J. S.

Page 86 note 1 Credner, H., Neues Jahrb. Min., 1847, p. 1 Google Scholar ; Ann. Phys. Chem. (Poggendorff), 1849, vol. 74, p. 546 ; C. Rammelsberg, ibid., p. 559.

Page 86 note 2 In error, A. Raimondi, Minéraux du Pérou, Paris 1878, p. 288, confused it with lampadite.

Page 89 note 1 Heddle, M. F., Phil. Mag., 1866, ser. 4, vol. 81, p. 258 Google Scholar ; Mineralogy of Scotland, 1901, vol. 2, p. 182.

Page 89 note 2 Goodchild, J. G., Geol. Mag., 1875, dec. 2 vol. 2, p. 565 CrossRefGoogle Scholar ; Trans. Cumberland and Westmorland Assoc. Adv. Lit. Sci., 1885, no. 9 (for 1883-4), p. 188. This mineral was also mentioned by S. G. Perceval from Treffgarn Rocks, Pembrokeshire (Geol. Mag., 1866, vol. 3, p. 377), but afterwards said to be ‘brookite’ (loc. cit., p. 518).

Page 90 note 1 Here was formerly a cell of the now ruined Glastonbury Abbey, and in the fifteenth century the ‘Prior of Greene Oare’ had differences with the miners.

Page 90 note 2 Woodward, J., loc. cit., vol. 10, pp. 208, 213Google Scholar ; vol. 2, pp. 27, 28.

Page 90 note 3 Perceval, S. G., Supplementary note on minerals found in Somersetshire. Geol. Mag., 1874 vol. 10 p. 166 CrossRefGoogle Scholar.

Page 92 note 1 Associated with small amounts of some copper-ore (not chalcopyrite, since there is no trace of iron in the nodules).

Page 92 note 2 See also Russell, A., Min. Mag., 1920, vol. 19, p. 64 CrossRefGoogle Scholar.