Robertsite Mineral Data

Robertsite Mineral Data
Search Webmineral :
   
Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images       News Help About


Dan Weinrich Fine Minerals
[Fine Minerals] [What's New] [Mineral Galleries] [My Collection] [Mineral Auctions]
Dan Weinrich Fine Minerals
Full-time professional mineral dealer with over 31 years experience in mineral collecting
And 15 years selling mineral specimens on the internet and at major mineral shows


General Robertsite Information

Help on Chemical Formula: Chemical Formula: Ca6Mn+++9(PO4)9O6(H2O)6•3(H2O)
Help on Composition: Composition: Molecular Weight = 1,739.69 gm
   Calcium     13.82 %  Ca   19.34 % CaO
   Manganese   28.42 %  Mn   36.70 % MnO
   Phosphorus  16.02 %  P    36.72 % P2O5
   Hydrogen     0.35 %  H     3.11 % H2O
   Oxygen      41.39 %  O
              ______        ______ 
              100.00 %       95.86 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca6Mn2+9(PO4)9O6•3(H2O)
Help on IMA Status: IMA Status: Approved IMA 1974
Help on Locality: Locality: Tip Top mine, Custer County, South Dakota, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Willard Lincoln Roberts (1923-1987), mineralogist, South Dakota School of Mines.
Help on Name Pronunciation: Name Pronunciation: Robertsite + Pronunciation Say ROBERTSITE
 

Robertsite Image

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

Robertsite   Carbonate-hydroxylapatite   Apatite

Comments: Black crystals of Robertsite on pink carbonate-hydroxylapatite.
Location: Tip Top mine, Custer, Custer County, South Dakota, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Robertsite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =0.8888:1:0.5785
Help on Cell Dimensions: Cell Dimensions: a = 17.36, b = 19.53, c = 11.3, Z = 4; beta = 96° V = 3,810.17 Den(Calc)= 3.03
Help on Crystal System: Crystal System: Monoclinic - PrismaticH-M Symbol (2/m) Space Group: A2/a
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 8.63(1), 2.74(0.6), 5.61(0.5),
 

Physical Properties of Robertsite

Help on Cleavage: Cleavage: {100} Good
Help on Color: Color: Blood red, Brownish black, Dark red, Reddish brown, Black.
Help on Density: Density: 3.17
Help on Diaphaneity: Diaphaneity: Translucent to Opaque
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Felted - Occurs as minute crystalling aggregates with the form of felt material.
Help on Hardness: Hardness: 3.5 - Copper Penny
Help on Luster: Luster: Adamantine
Help on Streak: Streak: brown
 

Optical Properties of Robertsite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.332 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.393 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2657,KPDmeas= 0.2539,KC= 0.1907
Ncalc = 1.58 - 1.6
Help on Optical Data: Optical Data: Biaxial (-), a=1.775, b=1.82, g=1.82, bire=0.0450, 2V(Calc)=0, 2V(Meas)=8.
 

Calculated Properties of Robertsite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.08 gm/cc
note: Specific Gravity of Robertsite =3.17 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0003857722
Boson Index = 0.9996142278
Help on Photoelectric: Photoelectric: PERobertsite = 9.75 barns/electron
U=PERobertsite x rElectron Density= 30.07 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Robertsite is Not Radioactive
 

Robertsite Classification
Help on Dana Class: Dana Class: 42.08.04.02 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.08)where (AB)7 (XO4)4 Zq · x(H2O)
  (42.08.04)Mitridatite Group
 
42.08.04.01 Mitridatite Ca2Fe3(PO4)3O2•3(H2O) A2/a 2/m
 
42.08.04.02 Robertsite Ca6Mn9(PO4)9O6(H2O)6•3(H2O) A2/a 2/m
 
42.08.04.03 Arseniosiderite Ca2Fe3(AsO4)3O2•3(H2O) A2/a 2/m
Help on Strunz Class: Strunz Class: 08.DH.30 08 - PHOSPHATES, ARSENATES, VANADATES
  08.D - Phosphates, etc
  08.DH -With large and medium-sized cations, (OH, etc.):RO4 < 1:1
 
08.DH.30 Arseniosiderite Ca2Fe3(AsO4)3O2•3(H2O) A2/a 2/m
 
08.DH.30 Pararobertsite Ca2Mn3(PO4)3O2•3(H2O) P 21/c 2/m
 
08.DH.30 Kolfanite Ca2Fe3O2(AsO4)3•2(H2O) A2/a 2/m
 
08.DH.30 Lunokite (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2(OH)•4(H2O) P bca 2/m 2/m 2/m
 
08.DH.30 Robertsite Ca6Mn9(PO4)9O6(H2O)6•3(H2O) A2/a 2/m
 
08.DH.30 Mitridatite Ca2Fe3(PO4)3O2•3(H2O) A2/a 2/m
 
08.DH.30 Sailaufite! Ca2Mn3O2(AsO4)2(CO3)•3(H2O) Cm m
 

Other Robertsite Information
Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Robertsite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - MinMax(Deutsch)
11 - MinMax(English)
12 - Mineralienatlas (Deutsch)
13 - QUT Mineral Atlas
14 - Ruff.Info

Search for Robertsite using:

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

Visit our Advertisers for Robertsite :

AA Mineral Specimens

B & L Fine Minerals

Crystalarium.com

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Desert Winds Gems and Minerals

Excalibur Minerals

Exceptional Minerals

Fabre Minerals

Heliodor

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

Wrights Rock Shop

Translate Robertsite Mineral Data :

Ask about Robertsite 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 Robertsite Specimen Label here :

Robertsite

Ca6Mn+++9(PO4)9O6(H2O)6•3(H2O)
Dana No: 42.08.04.02 Strunz No: 08.DH.30
Locality:

 

Notes: