Demicheleite-(I)
A valid IMA mineral species
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About Demicheleite-(I)
Formula:
BiSI
Colour:
dark red to black
Lustre:
Sub-Metallic
Specific Gravity:
6.411 (Calculated)
Crystal System:
Orthorhombic
Name:
Named for its relationship to demicheleite-(Br) and demicheleite-(Cl), with dominant I. The root name honors Vincenzo de Michele (b. 1936), former curator of the Natural History Museum, Milan, Italy.
I-dominant analogue of demicheleite-(Br) and demicheleite-(Cl). Unique combination of elements. The only Bi-I mineral known (compare the experimentally obtained phase: Unnamed (Pb-Bi iodide)). The other sulfide-iodide minerals are mutnovskite, perroudite, and radtkeite.
Unique Identifiers
Mindat ID:
39683
Long-form identifier:
mindat:1:1:39683:3
GUID
(UUID V4):
(UUID V4):
8be5044e-3b32-4f7d-9a71-d807fe39f9fe
IMA Classification of Demicheleite-(I)
Approved
Approval year:
2009
First published:
2010
Classification of Demicheleite-(I)
2.FC.
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
C : With Cl, Br, I (halide-sulfides)
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
C : With Cl, Br, I (halide-sulfides)
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference |
|---|---|---|
| Dem-I | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Demicheleite-(I)
Sub-Metallic
Transparency:
Translucent
Colour:
dark red to black
Streak:
Brown
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
None observed
Density:
6.411 g/cm3 (Calculated)
Chemistry of Demicheleite-(I)
Mindat Formula:
BiSI
Elements listed:
Crystallography of Demicheleite-(I)
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pnma
Cell Parameters:
a = 8.4501(7) Å, b = 10.1470(9) Å, c = 4.1389(4) Å
Ratio:
a:b:c = 0.833 : 1 : 0.408
Unit Cell V:
354.88 ų (Calculated from Unit Cell)
Morphology:
Prismatic, with dominant forms {110} and {111}.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.490 Å | (100) |
| 4.346 Å | (94) |
| 3.896 Å | (90) |
| 3.243 Å | (22) |
| 2.999 Å | (22) |
| 2.709 Å | (60) |
| 2.466 Å | (21) |
| 2.161 Å | (38) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 11 : Volcanic fumarole minerals; reduced phases (see also #45) |
Type Occurrence of Demicheleite-(I)
Place of Conservation of Type Material:
Dipartimento di Chimica Strutturale e Stereochimica Inorganica of Universita degli Studi di Milano, No. 2009-02.
Reference:
Demartin, F., Gramaccioli, C.M., Campostrini, I. (2010) Demicheleite-(I), BiSI, a new mineral from La Fossa Crater, Vulcano, Aeolian Islands, Italy. Mineralogical Magazine: 74: 141-145.
Synonyms of Demicheleite-(I)
Demicheleite (in part)
Common Associates
Associated Minerals Based on Photo Data:
| 1 photo of Demicheleite-(I) associated with Salammoniac | NH4Cl |
| 1 photo of Demicheleite-(I) associated with Bismuthinite | Bi2S3 |
Related Minerals - Strunz-mindat Grouping
| 2.FC.05 | Djerfisherite | K6(Fe,Cu,Ni)25S26Cl |
| 2.FC.05 | Thalfenisite | Tl6(Fe,Ni,Cu)25S26Cl |
| 2.FC.05 | Owensite | (Ba,Pb)6(Cu,Fe,Ni)25S27 |
| 2.FC.05 | Cu-djerfisherite | K6(Cu,Fe)25S26Cl |
| 2.FC.05 | Zoharite | (Ba,K)6(Fe,Cu,Ni)25S27 |
| 2.FC.05 | Gmalimite | K6◻Fe2+24S27 |
| 2.FC.10 | Bartonite | K6Fe20S26S |
| 2.FC.10 | Chlorbartonite | K6Fe24S26(Cl,S) |
| 2.FC.15a | Arzakite | Hg2+3S2(Br,Cl)2 |
| 2.FC.15a | Corderoite | Hg2+3S2Cl2 |
| 2.FC.15c | Grechishchevite | Hg2+3S2(Br,Cl,I)2 |
| 2.FC.15a | Lavrentievite | Hg2+3S2(Cl,Br)2 |
| 2.FC.15d | Radtkeite | Hg2+3S2ICl |
| 2.FC.15b | Kenhsuite | Hg2+3S2Cl2 |
| 2.FC.20a | Capgaronnite | AgHgClS |
| 2.FC.20c | Perroudite | Hg5Ag4S5(I,Br)2Cl2 |
| 2.FC.20b | Iltisite | HgAgSCl |
| 2.FC.20d | Hanauerite | AgHgSI |
| 2.FC.25 | Demicheleite-(Br) | BiSBr |
| 2.FC.25 | Demicheleite-(Cl) | BiSCl |
Fluorescence of Demicheleite-(I)
Not fluorescent
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.
Internet Links for Demicheleite-(I)
mindat.org URL:
https://www.mindat.org/min-39683.html
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External Links:
References for Demicheleite-(I)
Localities for Demicheleite-(I)
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and 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.
Czech Republic | |
| Dalibor Matýsek |
| Dalibor Matýsek | |
Italy (TL) | |
| Demartin et al. (2010) |
Poland | |
| Patryk Kosałka |
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La Fossa crater, Vulcano Island, Lipari, Eolie Islands, Metropolitan City of Messina, Sicily, Italy