Madocite

Pb19(Sb,As)16S43
IMA status
  • Approved
IMA symbol
Mdc
Discovered
1967
Also known as
  • IMA1966-015
  • Madociet
  • Madocite (of Jambor)

Where it forms, where it's found

Type locality
Taylor Pit
  1. Madoc
  2. Centre Hastings Municipality
  3. Hastings County
  4. Ontario
  5. Canada

44.5022°, -77.4664°

5recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Hardness
123456789103/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Transparency
Opaque
Colour
Grey-black
Streak
Grey-brack
Cleavage
Perfect

(010)

Fracture
Conchoidal

Optical

Pleochroism
Strong

White to gray, intensity slightly less than boulangerite

Anisotropism
Strong

Crystallography

Crystal system
Orthorhombic
Cell parameters
a = 27.2(2) Å · b = 34.1(2) Å · c = 4.06(5) Å
Ratio a:b:c
1 : 1.254 : 0.149
Z
4
Comment

Space group Pbam or Pba2. Strong pseudoperiod with c' = 0.5c.

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
82PbLeadLead19207.2003936.800
46.52%
51SbAntimonyAntimony16121.7601948.160
23.02%
16SSulfurSulfur4332.0601378.580
16.29%
33AsArsenicArsenic1674.9221198.752
14.17%
Total8462.292100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • IMA1966-015
  • Madociet
  • Madocite (of Jambor)

In other languages

French
madocite
German
IMA 1966-015 · Madocit
Spanish
madocite
Italian
madocite

Classification

Strunz
10th ed.

2.LB.30

  • 2Sulfides and SulfosaltsClass
  • 2.LUnclassified SulfosaltsDivision
  • 2.LBWith essential PbGroup
  • 2.LB.30MadociteSpecies
Dana
8th ed.

03.05.07.01

  • 03SulfosaltsClass
  • 03.052.5 < ø < 3Type
  • 03.05.07— unnamed intermediate level —Group
  • 03.05.07.01MadociteSpecies
CIM

5.6.14

  • 5Sulphosalts - Sulpharsenites and Sulphobismuthites (those containing Sn, Ge,or V are in Section 6)Class
  • 5.6Sulpharsenites etc. of Pb aloneGroup
  • 5.6.14MadociteSpecies

Literature, links & citation

Citations
  1. 1967Jambor, John Leslie (1967) New lead sulfantimonides from Madoc, Ontario. Part 1. The Canadian Mineralogist, 9 (1) 7-24
  2. 1968Mandarino, J.A.; Kato, A. (1968) New Mineral Names. American Mineralogist, 53 (7-8). 1421-1427
  3. 1968Jambor, John Leslie (1968) New lead sulfantimonides from Madoc, Ontario. Part 3--Syntheses, paragenesis, origin. The Canadian Mineralogist, 9 (4). 505-521
  4. 1973Walia, D. S., Chang, L. L. Y. (1973) Investigations in the systems PbS-Sb2S3-As2S3 and PbS-Bi2S3-As2S3. The Canadian Mineralogist, 12 (2) 113-119
  5. 1982Jambor, John L.; Laflamme, J. H. G.; Walker, D. A. (1982) A Re-examination of the Madoc Sulfosalts, in Ontario. The Mineralogical Record, 13 (2). 93-100
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Madocite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/madocite-2517},
  note      = {Accessed 2026-05-11}
}