Laphamite
This page kindly sponsored by Donald Lapham
About Laphamite
Davis M. Lapham
Formula:
As2Se3
Colour:
dark red
Lustre:
Resinous
Hardness:
1 - 2
Crystal System:
Monoclinic
Name:
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.
Type Locality:
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 )
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 Laphamite
Approved
Approval Year:
1985
First Published:
1986
2/F.02-80
2.FA.30
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
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
2.11.6.1
2 : SULFIDES
11 : AmBnXp, with (m+n):p = 2:3
2 : SULFIDES
11 : AmBnXp, with (m+n):p = 2:3
3.7.10
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
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 Laphamite
Resinous
Transparency:
Opaque
Colour:
dark red
Streak:
red-orange
Hardness:
1 - 2 on Mohs scale
Cleavage:
Perfect
Chemical Properties of Laphamite
Formula:
As2Se3
IMA Formula:
As2(Se,S)3
Elements listed:
Crystallography of Laphamite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 11.86 Å, b = 9.75 Å, c = 4.26 Å
β = 90.17°
β = 90.17°
Ratio:
a:b:c = 1.216 : 1 : 0.437
Unit Cell V:
492.60 ų (Calculated from Unit Cell)
Comment:
P21/n
Type Occurrence of Laphamite
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.
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.
Reference:
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 Laphamite
Other Language Names for Laphamite
Common Associates
Related Minerals - Nickel-Strunz Grouping
| 2.FA. | Anorpiment | As2S3 | Tric. 1 : P1 |
| 2.FA. | Bonazziite | As4S4 | Mon. 2/m : B2/b |
| 2.FA.05 | Duranusite | As4S | Orth. mmm (2/m 2/m 2/m) : Pmna |
| 2.FA.10 | Dimorphite | As4S3 | Orth. mmm (2/m 2/m 2/m) : Pnma |
| 2.FA.15b | Pararealgar | As4S4 | Mon. 2/m : P21/b |
| 2.FA.15a | Realgar | As4S4 | Mon. 2/m |
| 2.FA.15d | UM1970-18-S:As | As4S4 | Mon. 2/m : B2/b |
| 2.FA.20 | Alacránite | As8S9 | Mon. 2/m : P2/b |
| 2.FA.25 | Uzonite | As4S5 | Mon. |
| 2.FA.30 | Orpiment | As2S3 | Mon. 2/m |
| 2.FA.35 | Getchellite | AsSbS3 | Mon. 2/m : P21/b |
| 2.FA.40 | Wakabayashilite | [(As,Sb)6S9][As4S5] | Orth. mm2 : Pna21 |
Related Minerals - Hey's Chemical Index of Minerals Grouping
| 3.7.1 | Patrónite | VS4 | Mon. |
| 3.7.2 | Duranusite | As4S | Orth. mmm (2/m 2/m 2/m) : Pmna |
| 3.7.3 | Dimorphite | As4S3 | Orth. mmm (2/m 2/m 2/m) : Pnma |
| 3.7.4 | Realgar | As4S4 | Mon. 2/m |
| 3.7.5 | Pararealgar | As4S4 | Mon. 2/m : P21/b |
| 3.7.6 | Alacránite | As8S9 | Mon. 2/m : P2/b |
| 3.7.7 | Uzonite | As4S5 | Mon. |
| 3.7.8 | Orpiment | As2S3 | Mon. 2/m |
| 3.7.9 | Jeromite | Amor. | |
| 3.7.11 | Getchellite | AsSbS3 | Mon. 2/m : P21/b |
| 3.7.12 | Wakabayashilite | [(As,Sb)6S9][As4S5] | Orth. mm2 : Pna21 |
| 3.7.13 | Pääkkönenite | Sb2AsS2 | Mon. 2/m : B2/m |
| 3.7.14 | Stibnite | Sb2S3 | Orth. mmm (2/m 2/m 2/m) |
| 3.7.15 | Metastibnite | Sb2S3 | Amor. |
| 3.7.16 | Tellurantimony | Sb2Te3 | Trig. |
| 3.7.17 | Bismuthinite | Bi2S3 | Orth. mmm (2/m 2/m 2/m) |
| 3.7.18 | Nevskite | Bi(Se,S) | Trig. |
| 3.7.19 | Guanajuatite | Bi2Se3 | Orth. mmm (2/m 2/m 2/m) : Pnma |
| 3.7.21 | Ikunolite | Bi4(S,Se)3 | Trig. |
| 3.7.22 | Laitakarite | Bi4Se2S | Trig. 3m : R3m |
| 3.7.23 | Poubaite | PbBi2(Se,Te,S)4 | Trig. |
| 3.7.24 | Tellurobismuthite | Bi2Te3 | Trig. |
| 3.7.25 | Součekite | PbCuBi(S,Se)3 | Orth. |
| 3.7.26 | Tsumoite | BiTe | Trig. 3m (3 2/m) : P3 1m |
| 3.7.27 | Pilsenite | Bi4Te3 | Trig. 3m (3 2/m) : R3m |
| 3.7.28 | Hedleyite | Bi7Te3 | Trig. 3m (3 2/m) : R3m |
| 3.7.29 | Tetradymite | Bi2Te2S | Trig. 3m (3 2/m) : R3m |
| 3.7.30 | Joséite | Bi4TeS2 | Trig. 3m (3 2/m) : R3m |
| 3.7.31 | Joséite-B | Bi4Te2S | Trig. 3m (3 2/m) : R3m |
| 3.7.32 | Ingodite | Bi2TeS | Trig. |
| 3.7.33 | Sulphotsumoite | Bi3Te2S | Trig. |
| 3.7.34 | Kawazulite | Bi2Te2Se | Trig. |
| 3.7.36 | Skippenite | Bi2TeSe2 | Trig. |
| 3.7.37 | Kochkarite | PbBi4Te7 | Trig. |
| 3.7.38 | Rucklidgeite | PbBi2Te4 | Trig. |
| 3.7.39 | Aleksite | PbBi2Te2S2 | Trig. |
| 3.7.40 | Junoite | Cu2Pb3Bi8(S,Se)16 | Mon. 2/m : B2/m |
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 Laphamite
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 Laphamite
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https://www.mindat.org/min-2328.html
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Localities for Laphamite
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The Locality List
- 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).
All localities listed without proper references should be considered as questionable.
USA (TL) | |
| Mineralogical Magazine: 50:279 (1986), Dunn, et al. |
Burnside, Northumberland Co., Pennsylvania, USA