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This page kindly sponsored by Donald Lapham
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About LaphamiteHide

Davis M. Lapham
dark red
1 - 2
Crystal System:
Named in honor of Davis M. Lapham (5 May 1931, Glens Falls, New York, USA - 20 December 1974, Harrisburg, Pennsylvania, USA), former Chief Mineralogist of the Pennsylvania Geological Survey. In addition to his technical work, he wrote several collector-friendly publications including 'Mineral Collecting in Pennsylvania'. He was a founding member of the Friends of Mineralogy.
Isostructural with:
The Se analogue of orpiment. Compare kalgoorlieite - the chemical (Te) analogue, but not isostructural with laphamite.

Caveat: Some (or all?) of the photographs showing yellow acicular material might depict Se-bearing orpiment rather than laphamite. (See discussion at https://www.mindat.org/forum.php?read,7,361533,391404#msg-391404 )

Classification of LaphamiteHide

Approval Year:
First Published:

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
A : With As, (Sb), S

11 : AmBnXp, with (m+n):p = 2:3

3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
7 : Sulphides etc. of V, As, Sb and Bi

Physical Properties of LaphamiteHide

dark red
1 - 2 on Mohs scale

Chemical Properties of LaphamiteHide


Crystallography of LaphamiteHide

Crystal System:
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 11.86 Å, b = 9.75 Å, c = 4.26 Å
β = 90.17°
a:b:c = 1.216 : 1 : 0.437
Unit Cell V:
492.60 ų (Calculated from Unit Cell)

Type Occurrence of LaphamiteHide

Place of Conservation of Type Material:
The Natural History Museum, London, England, 1984,843 and E.1036.
National Museum of Natural History (Smithsonian), Washington, D.C., USA, 163039.
Geological Setting of Type Material:
Secondary mineral formed, probably by sublimation, on a clinker adjacent to a surface vent on a burning pile of coal.
Dunn, P.J., Peacor, D.R., Criddle, A.J., Finkelman, R.B. (1986) Laphamite, an arsenic selenide analogue of orpiment, from burning anthracite deposits in Pennsylvania. Mineralogical Magazine: 50: 279-282.

Synonyms of LaphamiteHide

Other Language Names for LaphamiteHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
Orpiment2 photos of Laphamite associated with Orpiment on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

2.FA.AnorpimentAs2S3Tric. 1 : P1
2.FA.BonazziiteAs4S4Mon. 2/m : B2/b
2.FA.05DuranusiteAs4SOrth. mmm (2/m 2/m 2/m) : Pmna
2.FA.10DimorphiteAs4S3Orth. mmm (2/m 2/m 2/m) : Pnma
2.FA.15bPararealgarAs4S4Mon. 2/m : P21/b
2.FA.15aRealgarAs4S4Mon. 2/m
2.FA.15dUM1970-18-S:AsAs4S4Mon. 2/m : B2/b
2.FA.20AlacrániteAs8S9Mon. 2/m : P2/b
2.FA.30OrpimentAs2S3Mon. 2/m
2.FA.35GetchelliteAsSbS3Mon. 2/m : P21/b
2.FA.40Wakabayashilite[(As,Sb)6S9][As4S5]Orth. mm2 : Pna21

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

3.7.2DuranusiteAs4SOrth. mmm (2/m 2/m 2/m) : Pmna
3.7.3DimorphiteAs4S3Orth. mmm (2/m 2/m 2/m) : Pnma
3.7.4RealgarAs4S4Mon. 2/m
3.7.5PararealgarAs4S4Mon. 2/m : P21/b
3.7.6AlacrániteAs8S9Mon. 2/m : P2/b
3.7.8OrpimentAs2S3Mon. 2/m
3.7.11GetchelliteAsSbS3Mon. 2/m : P21/b
3.7.12Wakabayashilite[(As,Sb)6S9][As4S5]Orth. mm2 : Pna21
3.7.13PääkköneniteSb2AsS2Mon. 2/m : B2/m
3.7.14StibniteSb2S3Orth. mmm (2/m 2/m 2/m)
3.7.17BismuthiniteBi2S3Orth. mmm (2/m 2/m 2/m)
3.7.19GuanajuatiteBi2Se3Orth. mmm (2/m 2/m 2/m) : Pnma
3.7.22LaitakariteBi4Se2STrig. 3m : R3m
3.7.26TsumoiteBiTeTrig. 3m (3 2/m) : P3 1m
3.7.27PilseniteBi4Te3Trig. 3m (3 2/m) : R3m
3.7.28HedleyiteBi7Te3Trig. 3m (3 2/m) : R3m
3.7.29TetradymiteBi2Te2STrig. 3m (3 2/m) : R3m
3.7.30JoséiteBi4TeS2Trig. 3m (3 2/m) : R3m
3.7.31Joséite-BBi4Te2STrig. 3m (3 2/m) : R3m
3.7.40JunoiteCu2Pb3Bi8(S,Se)16Mon. 2/m : B2/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 LaphamiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Kirkinskii, V.A., Yakushev, V.G. (1968) A new polymorphic modification of arsenic selenide obtained at high pressures (in English). Doklady Chemistry: 182: 896-898.
Kirkinskii, V.A., Yakushev, V.G. (1968) A new polymorphic modification of arsenic selenide obtained at high pressures (in Russian). Doklady Akademii Nauk SSSR: 182: 1083-1086.
Kirkinskii, V.A., Ryaposov, A.P., Yakushev, V.G. (1970) Synthesis of a third polymorphic modification of arsenic selenide at high pressure. Soviet Physics Solid State, USSR: 11: 1923-1924.
Zallen, R., Slade, M.L., Ward, A.T. (1971) Lattice vibrations and interlayer interactions in crystalline As2S3 and As2Se3. Physical Review B: 3: 4257-4273.
Stergiou, A.C., Rentzeperis, P.J. (1986) The crystal structure of arsenic selenide, As2Se3. Zeitschrift für Kristallographie: 173: 185–191.
Dunn, P.J., Peacor, D.R., Criddle, A.J., Finkelman, R.B. (1986) Laphamite, an arsenic selenide analogue of orpiment, from burning anthracite deposits in Pennsylvania. Mineralogical Magazine: 50: 279-282.
Hawthorne, F.C., Jambor, J.L., Bladh, K.W., Burke, E.A.J., Grice, J.D., Phillips, D., Roberts, A.C., Schedler, R.A., Shigley, J.E. (1987) New mineral names. American Mineralogist: 72: 1023-1028.
Bindi, L., Bonazzi, P., Spry, P.G. (2008) Effects of sulfur-for-selenium substitution on the structure of laphamite, As2(Se,S)3. The Canadian Mineralogist: 46: 269-274.
Anthony, J.W., Bideaux, R.A., Bladh, K.W., Nichols, M.C., Eds. Handbook of Mineralogy, Mineralogical Society of America, Chantilly, VA 20151-1110, USA. http://www.handbookofmineralogy.org/ (2016)

Internet Links for LaphamiteHide

Localities for LaphamiteHide

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.
  • Pennsylvania
    • Northumberland Co.
Mineralogical Magazine: 50:279 (1986), Dunn, et al.
Mineral and/or Locality  
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