VOOZH about

URL: https://www.mindat.org/min-2648.html

⇱ Mereheadite: Mineral information, data and localities.

👁 Image
Now Featuring: The Bruce Carter Collection at Heritage Auctions, Live May 16th
Log InRegister
AboutSupport UsPhotosDiscussionsSearchLearnMore

Mereheadite

A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.

About MereheaditeHide

This section is currently hidden. Click the show button to view.
Formula:
Pb47Cl25(OH)13O24(CO3)(BO3)2
Formula originally assumed to be Pb2O(OH)Cl.
Colour:
Pale yellow to reddish-orange
Lustre:
Vitreous, Resinous
Hardness:
3½
Specific Gravity:
7.12
Crystal System:
Monoclinic
Name:
Named after Merehead quarry, Somerset, the source of this and other unusual lead secondary minerals.
Related to symesite.


Unique IdentifiersHide

This section is currently hidden. Click the show button to view.
Mindat ID:
2648
Long-form identifier:
mindat:1:1:2648:8

IMA Classification of MereheaditeHide

This section is currently hidden. Click the show button to view.
Approved
IMA Formula:
Pb47O24(OH)13Cl25(BO3)2(CO3)
First published:
1998

Classification of MereheaditeHide

This section is currently hidden. Click the show button to view.
3.DC.45

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

Mineral SymbolsHide

This section is currently hidden. Click the show button to view.
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference
MrhIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of MereheaditeHide

This section is currently hidden. Click the show button to view.
Vitreous, Resinous
Transparency:
Transparent, Translucent
Colour:
Pale yellow to reddish-orange
Streak:
White
Hardness:
3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
(001)
Fracture:
Hackly, Conchoidal
Density:
7.12 g/cm3 (Measured)    7.31 g/cm3 (Calculated)

Optical Data of MereheaditeHide

This section is currently hidden. Click the show button to view.
Type:
Biaxial
RI values:
nα = 2.19 nγ = 2.28
Max. Birefringence:
δ = 0.090
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.

Surface Relief:
Moderate
Dispersion:
relatively strong
Reflectivity:
WavelengthR1 (%)R2 (%)
400nm17.20%17.95%
420nm16.50%17.40%
440nm15.90%16.90%
460nm15.50%16.50%
480nm15.10%16.10%
500nm14.90%15.80%
520nm14.50%15.50%
540nm14.30%15.30%
560nm14.10%15.20%
580nm14.00%15.00%
600nm13.90%14.90%
620nm13.80%14.80%
640nm13.80%14.80%
660nm13.70%14.70%
680nm13.60%14.65%
700nm13.60%14.60%


Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 17.95%.
R1 shown in black, R2 shown in
Colour in reflected light:
Gray
Internal Reflections:
Light yellow
Pleochroism:
Non-pleochroic

Chemistry of MereheaditeHide

This section is currently hidden. Click the show button to view.
Mindat Formula:
Pb47Cl25(OH)13O24(CO3)(BO3)2

Formula originally assumed to be Pb2O(OH)Cl.
Element Weights:
Element% weight
Pb85.369 %
Cl7.770 %
O6.452 %
B0.190 %
H0.115 %
C0.105 %

Calculated from ideal end-member formula.

Crystallography of MereheaditeHide

This section is currently hidden. Click the show button to view.
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 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°.

Crystal StructureHide

This section is currently hidden. Click the show button to view.
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File    Best | x | y | z | a | b | c
Rotation
Stop | Start
Labels
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0014589MereheaditeKrivovichev S V, Turner R, Rumsey M, Sidra O I, Kirk C A (2009) The crystal structure and chemistry of mereheadite Mineralogical Magazine 73 103-1172009Merehead Quarry, Cranmore, Somerset, England0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

This section is currently hidden. Click the show button to view.
Powder Diffraction Data:
d-spacingIntensity
2.930 Å(100)
3.785 Å(48)
2.825 Å(43)
6.581 Å(37)
2.182 Å(37)
2.780 Å(36)
3.267 Å(35)
Comments:
Merehead Quarry, Somerset, England. Data from the type description.

Geological EnvironmentHide

This section is currently hidden. Click the show button to view.
Paragenetic Mode(s):

Type Occurrence of MereheaditeHide

This section is currently hidden. Click the show button to view.
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.

Geological Setting of Type Material:
Lead bearing lenses and cavities in veins of manganese and iron oxide minerals that cut through a sequence of dolomitic limestone.
Associated Minerals at Type Locality:

Synonyms of MereheaditeHide

This section is currently hidden. Click the show button to view.

Other Language Names for MereheaditeHide

This section is currently hidden. Click the show button to view.

Common AssociatesHide

This section is currently hidden. Click the show button to view.
Associated Minerals Based on Photo Data:
24 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 CredneriteCu+Mn3+O2
6 photos of Mereheadite associated with ParkinsonitePb7MoO9Cl2
6 photos of Mereheadite associated with ParalaurionitePbCl(OH)
3 photos of Mereheadite associated with MimetitePb5(AsO4)3Cl
3 photos of Mereheadite associated with DiaboleitePb2CuCl2(OH)4
3 photos of Mereheadite associated with HydrocerussitePb3(CO3)2(OH)2
3 photos of Mereheadite associated with PlumbonacritePb5O(OH)2(CO3)3

Related Minerals - Strunz-mindat GroupingHide

This section is currently hidden. Click the show button to view.
3.DC.GajardoiteKCa0.5As3+4O6Cl2 · 5H2OHex. 6/mmm(6/m2/m2/m) : P6/mmm
3.DC.Lucabindiite(K,NH4)As4O6(Cl,Br)Hex. 6/mmm(6/m2/m2/m) : P6/mmm
3.DC.Cuatrocapaite-(NH4)(NH4)3(NaMg◻)(As2O3)6Cl6 · 16H2OTrig. 3m(32/m) : R3m
3.DC.Cuatrocapaite-(K)K3(NaMg◻)(As2O3)6Cl6 · 16H2OTrig. 3m(32/m) : R3m
3.DC.NapoliitePb2OFClTet. 4/mmm(4/m2/m2/m) : P42/mcm
3.DC.TorrecillasiteNa(As,Sb)3+4O6ClOrth.
3.DC.05ParalaurionitePbCl(OH)Mon. 2/m : B2/m
3.DC.05LaurionitePbCl(OH)Orth. mmm(2/m2/m2/m)
3.DC.05Mauriziodiniite(NH4)(As2O3)2IHex. 6/mmm(6/m2/m2/m) : P6/mmm
3.DC.05Russoite(NH4)ClAs2O3(H2O)0.5Hex. 622 : P622
3.DC.10FiedleritePb3FCl4(OH) · H2OMon. 2/m
3.DC.15PenfielditePb2Cl3(OH)Hex. 6 : P6
3.DC.15TelluroperitePb3TeO4Cl2Orth. mmm(2/m2/m2/m)
3.DC.20LaurelitePb7F12Cl2Hex. 6 : P6
3.DC.25ZhangpeishaniteBaFClTet. 4/mmm(4/m2/m2/m) : P4/nmm
3.DC.25MatlockitePbFClTet. 4/mmm(4/m2/m2/m) : P4/nmm
3.DC.25Zavaritskite(BiO)FTet. 4/mmm(4/m2/m2/m) : P4/nmm
3.DC.25RorisiteCaFClTet. 4/mmm(4/m2/m2/m) : P4/nmm
3.DC.25BismocliteBiOClTet. 4/mmm(4/m2/m2/m) : P4/nmm
3.DC.25VegrandisiteBaCl2Orth. mmm(2/m2/m2/m) : Pnma
3.DC.30NadoritePbSbClO2Orth. mmm(2/m2/m2/m) : Cmcm
3.DC.30PeritePbBiClO2Orth. mmm(2/m2/m2/m) : Cmcm
3.DC.40ThorikositePb3Cl2(OH)(SbO3,AsO3)Tet. 4/mmm(4/m2/m2/m) : I4/mmm
3.DC.50BlixitePb8O5(OH)2Cl4Orth.
3.DC.52RumseyitePb2OClF Tet. 4/mmm(4/m2/m2/m) : I4/mmm
3.DC.55Vladkrivovichevite[Pb32O18][Pb4Mn2O]Cl14(BO3)8 · 2H2O Orth. mmm(2/m2/m2/m) : Pmmn
3.DC.55PinalitePb3WO5Cl2Orth. mmm(2/m2/m2/m)
3.DC.57YeomanitePb2O(OH)ClOrth. mmm(2/m2/m2/m) : Pnma
3.DC.60SymesitePb10(SO4)O7Cl4 · H2OTric. 1 : P1
3.DC.60LorettoitePb7O6Cl2Orth.
3.DC.62Sarawakite (of Frenzel)Sb, O, Cl (?)
3.DC.65EcdemitePb6As3+2O7Cl4Mon. 2 : P21
3.DC.70MendipitePb3Cl2O2Orth. 222 : P212121
3.DC.75DamaraitePb3Cl(OH)O2Orth. mm2 : Pmc21
3.DC.80OnoratoiteSb8Cl2O11Tric. 1 : P1
3.DC.95BarstowitePb4Cl6(CO3) · H2OMon. 2/m : P21/m

Fluorescence of MereheaditeHide

This section is currently hidden. Click the show button to view.
Not fluorescent.

Other InformationHide

This section is currently hidden. Click the show button to view.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for MereheaditeHide

This section is currently hidden. Click the show button to view.
mindat.org URL:
https://www.mindat.org/min-2648.html
Please feel free to link to this page.

References for MereheaditeHide

This section is currently hidden. Click the show button to view.

Localities for MereheaditeHide

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

Locality ListHide

This section is currently hidden. Click the show button to view.
👁 Image
- This locality has map coordinates listed. 👁 Image
- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. 👁 Image
- Good crystals or important locality for species. 👁 Image
- 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 (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Argentina
  • La Rioja Province
    • General Lamadrid Department
      • Villa Castelli
Grundmann et al. (2018)
  • Mendoza Province
    • Luján de Cuyo department
      • Cacheuta District
        • Sierra de Cacheuta
          • Cerro de Cacheuta
Grundmann et al. (2018)
Germany
  • Baden-Württemberg
    • Freiburg Region
      • Ortenaukreis
        • Oberwolfach
Walenta (1999) +1 other reference
  • North Rhine-Westphalia
    • Arnsberg
      • Hochsauerlandkreis
        • Brilon
Rouse et al. (1990) +1 other reference
UK
  • England
    • Bristol
      • Westbury on Trym
Day (1999)
    • Somerset
      • Mendip
        • Cranmore
Alabaster (1989) +7 other references
Quick NavTopAbout MereheaditeUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 4, 2026 07:18:40 Page updated: February 19, 2026 19:21:56
Go to top of page