SUPPORT US. If is important to you, click here to donate to our Fall 2019 fundraiser!
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography


This page is currently not sponsored. Click here to sponsor this page.
Hide all sections | Show all sections

About MereheaditeHide

Torr Works Quarry General View, July 2005

Torr Works Quarry, Cranmore, Mendip, Somerset, England, UK
Formula originally assumed to be Pb2O(OH)Cl.
pale yellow to reddish-orange
Vitreous, Resinous
Specific Gravity:
Crystal System:
Named after Merehead quarry, Somerset, the source of this and other unusual lead secondary minerals.
Related to symesite.

Classification of MereheaditeHide

First Published:

D : Oxyhalides, hydroxyhalides and related double halides
C : With Pb (As,Sb,Bi), without Cu

Physical Properties of MereheaditeHide

Vitreous, Resinous
Transparent, Translucent
pale yellow to reddish-orange
3½ on Mohs scale
Hackly, Conchoidal
7.12 g/cm3 (Measured)    7.31 g/cm3 (Calculated)

Optical Data of MereheaditeHide

RI values:
nα = 2.190 nγ = 2.280
Max Birefringence:
δ = 0.090
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
relatively strong

Chemical Properties of MereheaditeHide


Formula originally assumed to be Pb2O(OH)Cl.
IMA Formula:

Crystallography of MereheaditeHide

Crystal System:
Class (H-M):
m - Domatic
Cell Parameters:
a = 17.372(1) Å, b = 27.9419(19) Å, c = 10.6661(6) Å
β = 93.152(5)°
a:b:c = 0.622 : 1 : 0.382
Unit Cell V:
5169.6 ų
SG Cm; originally reported cell (Welch et al., 1998): C2/c, 5.680, 5.565, 13.143 A, 90.64°.

Type Occurrence of MereheaditeHide

General Appearance of Type Material:
polycrystalline aggregates, up to 10 x 30 mm, in which individual grains are anhedral and rarely exceed 2 mm.
Place of Conservation of Type Material:
Natural History Museum, London, England, specimen BM 1965,285 and polished mount E.1175.

Synonyms of MereheaditeHide

Other Language Names for MereheaditeHide


Common AssociatesHide

Associated Minerals Based on Photo Data:
15 photos of Mereheadite associated with MendipitePb3Cl2O2
10 photos of Mereheadite associated with ChloroxiphitePb3CuO2Cl2(OH)2
9 photos of Mereheadite associated with RickturneritePb7O4[Mg(OH)4](OH)Cl3
7 photos of Mereheadite associated with CredneriteCuMnO2
3 photos of Mereheadite associated with PlumbonacritePb5O(OH)2(CO3)3
3 photos of Mereheadite associated with ParkinsonitePb7MoO9Cl2
3 photos of Mereheadite associated with DiaboleitePb2CuCl2(OH)4
2 photos of Mereheadite associated with HydrocerussitePb3(CO3)2(OH)2
2 photos of Mereheadite associated with SymesitePb10(SO4)O7Cl4 · H2O
1 photo of Mereheadite associated with CalciteCaCO3

Related Minerals - Nickel-Strunz GroupingHide

3.DC.05LaurionitePbCl(OH)Orth. mmm (2/m 2/m 2/m)
3.DC.05ParalaurionitePbCl(OH)Mon. 2/m : B2/m
3.DC.10FiedleritePb3FCl4(OH) · H2OMon. 2/m
3.DC.15PenfielditePb2Cl3(OH)Hex. 6 : P6
3.DC.20LaurelitePb7F12Cl2Hex. 6 : P6
3.DC.25BismocliteBiOClTet. 4/mmm (4/m 2/m 2/m) : P4/nmm
3.DC.25Daubréeite(BiO)(OH,Cl)Tet. 4/mmm (4/m 2/m 2/m) : P4/nmm
3.DC.25MatlockitePbFClTet. 4/mmm (4/m 2/m 2/m) : P4/nmm
3.DC.25ZhangpeishaniteBaFClTet. 4/mmm (4/m 2/m 2/m) : P4/nmm
3.DC.30NadoritePbSbClO2Orth. mmm (2/m 2/m 2/m) : Cmcm
3.DC.30PeritePbBiClO2Orth. mmm (2/m 2/m 2/m) : Cmcm
3.DC.35AravaipaitePb3AlF9 · H2OTric.
3.DC.37CalcioaravaipaitePbCa2AlF9Tric. 1
3.DC.40ThorikositePb3Cl2(OH)(SbO3,AsO3)Tet. 4/mmm (4/m 2/m 2/m) : I4/mmm
3.DC.60SymesitePb10(SO4)O7Cl4 · H2OTric. 1 : P1
3.DC.65EcdemitePb6Cl4(As2O7)Mon. 2 : P21
3.DC.70MendipitePb3Cl2O2Orth. 2 2 2 : P21 21 21
3.DC.75DamaraitePb3Cl(OH)O2Orth. mm2 : Pmc21
3.DC.80OnoratoiteSb8Cl2O11Tric. 1 : P1
3.DC.85CotunnitePbCl2Orth. mmm (2/m 2/m 2/m)
3.DC.95BarstowitePb4Cl6(CO3) · H2OMon. 2/m : P21/m

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for MereheaditeHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Welch, M.D., Criddle, A.J., and Symes, R.F. (1998) Mereheadite, Pb2O(OH)Cl: a new litharge-related oxychloride from Merehead Quarry, Cranmore, Somerset. Mineralogical Magazine: 62: 387-393.
Jambor, J.L., Pertsev, N.N., and Roberts, A.C. (1999) New mineral names. American Mineralogist: 84: 1195-1198.
Krivovichev, S.V., Turner, R., Rumsey, M., Siidra, O.I., and Kirk, C.A. (2009) The crystal structure and chemistry of mereheadite. Mineralogical Magazine: 73: 103-117.

Internet Links for MereheaditeHide

Localities for MereheaditeHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • La Rioja Province
    • General Lamadrid department
      • Villa Castelli
Grundmann, G., & Förster, H. J. (2018). The Sierra de Cacheuta Vein-Type Se Mineralization, Mendoza Province, Argentina. Minerals, 8(4), 127.
  • Baden-Württemberg
    • Freiburg
      • Ortenaukreis
        • Oberwolfach
WALENTA, K. (1999): Neue Mineralfunde von der Grube Clara. 8. Folge, 2. Teil. Lapis 24 (12), 40-44; KOLITSCH, U. (2000): Eine durch Betoneinwirkung entstandene Paragenese von Blei-Verbindungen aus der Grube Clara im mittleren Schwarzwald. Erzgräber 14, 48-53. [discussion of the mereheadite reported by Walenta (1999)].
  • North Rhine-Westphalia
    • Arnsberg
      • Hochsauerlandkreis
        • Brilon
Rouse, R. C. and Dunn, P. J. (1990): A new lead sulfate oxychloride related to the nadorite group from Brilon, Germany. Neues Jahrb. Mineral. Monatsh. 1990, 337-342; Turner, R.W., Siidra, O.I., Rumsey, M.S., Polekhovsky, Y.S., Kretser, Y.L., Krivovichev, S.V., Spratt, J., Stanley, C.J. (2015): Yeomanite, Pb2O(OH)Cl, a new chain-structured Pb oxychloride from Merehead Quarry, Somerset, England. Mineralogical Magazine, 79, 1203-1211.
  • England
    • Bristol
      • Westbury on Trym
BMS Database
    • Somerset
      • Mendip
        • Cranmore
Alabaster, C. (1989) The Wesley Mine; a further occurrence of manganese-oxide hosted lead oxychloride minerals in the Bristol District. Journal of the Russell Society: 2(2): 29-47.; Welch, M.D., Criddle, A.J., and Symes, R.F. (1998) Mereheadite, Pb2O(OH)Cl: a new litharge-related oxychloride from Merehead Quarry, Cranmore, Somerset. Mineralogical Magazine: 62: 387-393.; Jambor, J.L., Pertsev, N.N., and Roberts, A.C. (1999) New mineral names. American Mineralogist: 84: 1195-1198.; Turner, R.W. (2005) A new find of lead oxychlorides at Torr Works, Somerset. Russell Society Newsletter: 47 (September 2005).; Turner, R.W. (2006) A mechanism for the formation of the mineralised Mn deposits at Merehead Quarry, Cranmore, Somerset, England. Mineralogical Magazine: 70(6): 629-653.; Krivovichev, S.V., Turner, R.W., Rumsey, M.S., Siidra, O.I., and Kirk, C.A. (2009) The crystal structure and chemistry of mereheadite. Mineralogical Magazine: 73: 75-89.; Turner, R.W. and Rumsey, M.S. (2010) Mineral relationships in the Mendip Hills. Journal of the Russell Society: 13: 3-46.;
Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © and the Hudson Institute of Mineralogy 1993-2019, except where stated. Most political location boundaries are © OpenStreetMap contributors. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: October 23, 2019 08:47:51 Page generated: October 23, 2019 04:52:51
Go to top of page