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|"1:1" layer silicate where the Fe2(Si2O5)O3(OH) part of the formula is analogous in structure to kaolinite, Al2(Si2O5)(OH)4, but additional Sb3+ is in pyramidal coordinate over the "holes" in the Fe layer.|
|System:||Monoclinic||Colour:||Olive green to deep ...|
|Name:||For John Edward Chapman (1821-1904) Professor of geology, University of Toronto|
The antimony analogue of Bismutoferrite, with which it is easily confused.
Classification of Chapmanite
|IMA status:||Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"|
|Strunz 8th edition ID:||8/B.06-10|
|Nickel-Strunz 10th (pending) edition ID:||9.ED.25|
9 : SILICATES (Germanates)
E : Phyllosilicates
D : Phyllosilicates with kaolinite layers composed of tetrahedral and octahedral nets
|Dana 8th edition ID:||184.108.40.206|
71 : PHYLLOSILICATES Sheets of Six-Membered Rings
1 : Sheets of 6-membered rings with 1:1 layers
|Hey's CIM Ref.:||17.7.20|
17 : Silicates Containing other Anions
7 : Silicates with vanadate, arsenate or antimonate
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Type Occurrence of Chapmanite
|Type Locality:||Keeley-Frontier Mine (Canadian Keeley; Frontier Mine; Keeley Mine), South Lorrain Township, Cobalt-Gowganda region, Timiskaming District, Ontario, Canada|
|Place of Conservation of Type Material:||ROM and Harvard|
|Year of Discovery:||1924|
Physical Properties of Chapmanite
|Colour:||Olive green to deep yellow|
|Streak:||Greenish yellow to deep yellow|
|Density (measured):||3.69 - 3.75 g/cm3|
|Density (calculated):||4.29 g/cm3|
Crystallography of Chapmanite
|Class (H-M):||m - Domatic|
|Space Group Setting:||Cm|
|Cell Parameters:||a = 5.19Å, b = 8.99Å, c = 7.70Å|
β = 100.4°
|Ratio:||a:b:c = 0.577 : 1 : 0.857|
|Unit Cell Volume:||V 353.37 Å³ (Calculated from Unit Cell)|
|Morphology:||Crystals lath shaped, powdery, compact, massive|
Optical Data of Chapmanite
|RI values:||nα = 1.850 nβ = 1.950 nγ = 1.960|
|Maximum Birefringence:||δ = 0.110|
Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
|Surface Relief:||Very High|
Chemical Properties of Chapmanite
"1:1" layer silicate where the Fe2(Si2O5)O3(OH) part of the formula is analogous in structure to kaolinite, Al2(Si2O5)(OH)4, but additional Sb3+ is in pyramidal coordinate over the "holes" in the Fe layer.
|Simplified for copy/paste:||Fe3+2Sb3+(Si2O5)O3(OH)|
|Essential elements:||Fe, H, O, Sb, Si|
|All elements listed in formula:||Fe, H, O, Sb, Si|
Relationship of Chapmanite to other Species
|Related Minerals - Nickel-Strunz Grouping):|
|Related Minerals - Hey's Index Grouping:|
Other Names for Chapmanite
|Health Warning:||No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.|
References for Chapmanite
WALKER, T.L. (1924): Chapmanite, a new hydrous ferrous silica-antimonate from South Lorrain, Ontario. Contributions to Canadian Mineralogy, University of Toronto, Geology Series 17, 5-8.
Milton, C., J.M. Axelrod, and B. Ingram (1958): Bismutoferrite, chapmanite, and "hypochlorite". American Mineralogist, 43, 656-670.
ZHUKHLISTOV, A.P. & ZVYAGIN, B.B. (1977): Determination of the crystal structures of chapmanite and bismutoferrite by high-voltage electron diffraction. Kristallografiya 22, 731-738. (in Russian). in English: Soviet Physics and Crystallography 22, 419-423.
Powder Diffraction: 13(1): 44-49.
Internet Links for Chapmanite
Localities for Chapmanite
The 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.
(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.