Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Mereheadite

This page is currently not sponsored. Click here to sponsor this page.
Formula:
Pb47Cl25(OH)13O24(CO3)(BO3)2
Formula originally assumed to be Pb2O(OH)Cl.
System:
Monoclinic
Colour:
Pale yellow
Hardness:
Name:
Named after Merehead quarry, Somerset, source of this and other unusual lead secondary minerals.
Related to symesite.

Classification of Mereheadite

Approved
3.DC.45

3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
C : With Pb (As,Sb,Bi), without Cu
mindat.org URL:
http://www.mindat.org/min-2648.html
Please feel free to link to this page.

First Recorded Occurrence of Mereheadite

Physical Properties of Mereheadite

Vitreous, Resinous
Colour:
Pale yellow
Streak:
White
Hardness (Mohs):

Crystallography of Mereheadite

Crystal System:
Monoclinic
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)°
Ratio:
a:b:c = 0.622 : 1 : 0.382
Unit Cell Volume:
V 5169.6 ų
Comment:
SG Cm; originally reported cell (Welch et al., 1998): C2/c, 5.680, 5.565, 13.143 A, 90.64°.

Optical Data of Mereheadite

Type:
Biaxial
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:
Moderate
Dispersion:
relatively strong

Chemical Properties of Mereheadite

Formula:
Pb47Cl25(OH)13O24(CO3)(BO3)2

Formula originally assumed to be Pb2O(OH)Cl.
Essential elements:
All elements listed in formula:

Relationship of Mereheadite to other Species

3.DC.05LaurionitePbCl(OH)
3.DC.05ParalaurionitePbCl(OH)
3.DC.10FiedleritePb3FCl4(OH) · H2O
3.DC.15PenfielditePb2Cl3(OH)
3.DC.20LaurelitePb7F12Cl2
3.DC.25Bismoclite(BiO)Cl
3.DC.25Daubréeite(BiO)(OH,Cl)
3.DC.25MatlockitePbFCl
3.DC.25RorisiteCaFCl
3.DC.25Zavaritskite(BiO)F
3.DC.25ZhangpeishaniteBaFCl
3.DC.30NadoritePbSbClO2
3.DC.30PeritePbBiClO2
3.DC.35AravaipaitePb3F3[AlF6] · H2O
3.DC.37CalcioaravaipaitePbCa2AlF9
3.DC.40ThorikositePb3Cl2(OH)(SbO3,AsO3)
3.DC.50BlixitePb2(O,OH)2Cl
3.DC.55PinalitePb3WO5Cl2
3.DC.60SymesitePb10(SO4)O7Cl4 · H2O
3.DC.65EcdemitePb6Cl4(As2O7)
3.DC.65HeliophyllitePb6Cl4(As2O7)
3.DC.70MendipitePb3Cl2O2
3.DC.75DamaraitePb3Cl(OH)O2
3.DC.80OnoratoiteSb8Cl2O11
3.DC.85CotunnitePbCl2
3.DC.90PseudocotunniteK2PbCl4
3.DC.95BarstowitePb4Cl6(CO3) · H2O

Other Names for Mereheadite

Name in Other Languages:
German:Mereheadit
Spanish:Mereheadita

Other Information

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 Mereheadite

Reference List:
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.

Krivovichev, S.V., Turner, R., Rumsey, M., Siidra, O.I., Kirk. C.A. (2009): The crystal structure and chemistry of mereheadite. Mineralogical Magazine, 73, 103-117.

Internet Links for Mereheadite

Localities for Mereheadite

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.
(TL) indicates type locality for a valid mineral species. (FRL) indicates first recorded locality for everything else. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
Germany
 
  • Baden-Württemberg
    • Black Forest
      • Wolfach
        • Oberwolfach
          • Rankach valley
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)].
UK
 
  • England
    • Bristol
      • Westbury on Trym
BMS Database
    • Somerset
      • Cranmore
[Min.Mag.(1998) 62, 387-393; J. Russel Soc 2:2 p29]; Turner, R.W., (2005) A New Find of Lead Oxychlorides at Torr Works, Somerset. Russell Society Newsletter, No. 47, September 2005; Turner, R.W., (2006) A Mechanism for the formation of the Mineralised Mn Deposits at Merehead Quarry, Cranmore, Somerset, England. Min. Mag. vol. 70, no. 6, pp 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, vol 13, pp 3-46;
Mineral and/or Locality  
Copyright © mindat.org 1993-2015, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: January 27, 2015 21:03:04 Page generated: January 21, 2015 14:23:46