Sewardite Mineral Data

AA Mineral Sepcimens
[What's New] [Mineral Galleries] [Sale Items] [About Us] [Contacts]
At AA Mineral Specimens, we source quality Mineral Specimens, Fossils, Gemstones,
Decorative Stones, Lapidary Material and Specimen Sets world-wide

General Sewardite Information
Help on Chemical Formula: Chemical Formula: CaFe+++2(AsO4)2(OH)2
Help on Composition: Composition: Molecular Weight = 464.68 gm
   Calcium    8.62 %  Ca   12.07 % CaO
   Zinc       1.41 %  Zn    1.75 % ZnO
   Iron      22.83 %  Fe   32.65 % Fe2O3
   Arsenic   32.25 %  As   49.46 % As2O5
   Hydrogen   0.46 %  H     4.07 % H2O
   Oxygen    34.43 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaFe3+1.9Zn0.1(AsO4)2(OH)1.9(H2O)0.1
Help on Environment: Environment: Intergrown with ferrilotharmeyerite and another unknown. (Ca-dominant analogue of carminite; structure)
Help on IMA Status: IMA Status: Approved IMA 2002 (Dana # Added)
Help on Locality: Locality: 31st Level, Tsumeb mine, Tsumeb, Namibia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Terry Maxwell Seward (1940-) who collected the mineral.
Help on Synonym: Synonym: IMA2001-054
 

Sewardite Image

Click Here for Larger Sewardite Image in a New Browser Window Images:
Click Here for Larger Sewardite Image

Sewardite

Comments: Photomicrograph of an isolated fragment of red sewardite as well as a fragment in green to black botryoidal matrix.
Location: Single specimen of gangue collected from the 31st level of the Tsumeb mine, Tsumeb, Namibia. Scale: See Image.
© Canadian Mineralogist
Click Here for Larger Sewardite Image in a New Browser Window Images:
Click Here for Larger Sewardite Image

Sewardite

Comments: Deep red, micaceous sewardite crystals mistakenly identified as carminite.
Location: Benjamin Hill, Sonora, Mexico. Scale: Picture size 1 cm.
© Tom Loomis / Dakota Matrix

Sewardite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =2.2142:1:1.6318
Help on Cell Dimensions: Cell Dimensions: a = 16.461, b = 7.434, c = 12.131, Z = 8; V = 1,484.48 Den(Calc)= 4.16
Help on Crystal System: Crystal System: Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: C ccm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.167(1)(022), 2.503(0.9)(422,314), 4.874(0.9)(202),2.919(0.7)(511), 3.389(0.6)(220), 1.775(0.5)(026), 2.988(0.5)(313), 3.015(0.5)(510), 3.473(0.5)(113),
Click Here for Large Sewardite Structure Window Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
 Help on Above


Roberts A C , Cooper M A , Hawthorne F C , Criddle A J , Stirling J A R , The Canadian Mineralogist , 40 (2002) p.1191-1198, Sewardite, CaFe2(AsO4)(OH)2, the Ca-analogue of carminite,, from Tsumeb, Namibia: Description and crystal structure, Locality: Tsumeb, Namibia

 

Physical Properties of Sewardite

Help on Cleavage: Cleavage: [100] Imperfect, [011] Imperfect
Help on Color: Color: Dark red, Lighter red orange.
Help on Diaphaniety: Diaphaniety: Translucent
Help on Fracture: Fracture: Splintery - Thin, elongated fractures produced by intersecting good cleavages or partings (e.g. hornblende).
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Anhedral Grains - Granular minerals without the expression of crystal shapes
Help on Habit: Habit: Platy - Sheet forms (e.g. micas).
Help on Hardness: Hardness: 3.5 - Copper Penny
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: reddish brown
 

Optical Properties of Sewardite

Help on Optical Data: Optical Data: NCalc= 1.94 - from Gladstone-Dale relationship (KC = 0.2249) where Ncalc=Dcalc*KC+1
Help on RL Anisotrophism: RL Anisotrophism: None.
Help on RL Bireflectance: RL Bireflectance: Weak.
Help on RL Color: RL Color: Light bluish gray with bright pink to red internal reflections.
Help on RL Pleochroism: RL Pleochroism: None.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Sewardite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 460 nm   10.12   10.71 
   
 540 nm    9.53   10.07 
 580 nm    9.30    9.98 
 640 nm    8.99    9.66 
Calculated Relative Intensity Colors of Sewardite in Air
Relative
Intensity		    0% 100% 200% 300% 400% 500% 600% 700% 800% 900% 950%
R1                      
R2                      
 

Calculated Properties of Sewardite

Help on Electron Density: Electron Density:

relectron=3.95 gm/cc
note: rSewardite =4.16 gm/cc.
Help on Fermion Index Fermion Index Fermion Index = 0.0057
Boson Index = 0.9943
Help on Photoelectric: Photoelectric:

PESewardite = 30.83 barns/electron
U=PESewardite x relectron= 121.72 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Sewardite is Not Radioactive
 

Sewardite Classification
Help on Dana Class: Dana Class: 41.10.6.2 (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen
  (41.10)where (A++ B++)3 (XO4)2 Zq
  (41.10.6)Dana Group
 
41.10.6.1 Carminite PbFe2(AsO4)2(OH)2 C ccm 2/m 2/m 2/m
 
41.10.6.2 Sewardite ! CaFe2(AsO4)2(OH)2 C ccm 2/m 2/m 2/m
Help on Strunz Class: Strunz Class: VII/B.28-35 VII - Phosphates, Arsenates and Vanadates
  VII/B - Waterfree phosphates with unfamiliar anions F, Cl, O, OH. cations of medium and big size: Mg, Cu, Zn, and Ca, Na, K, Ba, Pb
  VII/B.28 - Carminite series
 
VII/B.28-10 Bertossaite Li2CaAl4(PO4)4(OH)4 Imaa,Iaa2 Ortho
 
VII/B.28-20 Palermoite (Sr,Ca)(Li,Na)2Al4(PO4)4(OH)4 I mmm 2/m 2/m 2/m
 
VII/B.28-30 Attakolite (Ca,Sr)Mn(Al,Fe)4[(Si,P)O4]H(PO4)3(OH)4 C 2/m 2/m
 
VII/B.28-35 Sewardite CaFe2(AsO4)2(OH)2 C ccm 2/m 2/m 2/m
 
VII/B.28-40 Carminite PbFe2(AsO4)2(OH)2 C ccm 2/m 2/m 2/m
 
VII/B.28-60 Leningradite PbCu3(VO4)Cl2 I bam 2/m 2/m 2/m
 
VII/B.28-70 Namibite CuBi2(VO4)O2 C 2/m,Cm,C 2 Mono
 
VII/B.28-80 Paganoite! (Ni,Co)BiAsO5 P1 1
 

Other Sewardite Information
Help on References: References: NAME( AmMin, v 88, p 1178) PHYS. PROP.(AmMin, v 88, p 1178) OPTIC PROP.(AmMin, v 88, p 1178)
Help on See Also: See Also: Links to other databases for Sewardite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -MinDAT 6 -MinMax(Deutsch) 7 -MinMax(English) 8 -Mineralienatlas (Deutsch) 9 -QUT Mineral Atlas

Search for Sewardite using:

Google
 
Web webmineral.com
[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Sewardite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Sewardite Mineral Data :

Ask about Sewardite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Espaņol

Print or Cut-and-Paste your Sewardite Specimen Label here :

Sewardite

CaFe+++2(AsO4)2(OH)2
Dana No: 41.10.6.2 Strunz No: VII/B.28-35
Locality:

 

Notes:

 
 
   
 
Go To Webmineral Home Crystallography X-Ray D-Spacing Table Chemical Composition
Dana Classification Strunz Classification Table of Mineral Properties Alphabetical Listing of Minerals
Search Webmineral Photo Gallery of Mineral Images Help Files Links