Mineralogy Database

Montgomeryite Mineral Data

Search Webmineral :

General Montgomeryite Information

Help on Chemical  Formula: Chemical Formula: Ca4MgAl4(PO4)6(OH)4•12(H2O)
Help on Composition: Composition: Molecular Weight = 1,146.58 gm
   Calcium     13.98 %  Ca   19.56 % CaO
   Magnesium    2.12 %  Mg    3.52 % MgO
   Aluminum     9.41 %  Al   17.79 % Al2O3
   Phosphorus  16.21 %  P    37.14 % P2O5
   Hydrogen     2.46 %  H    22.00 % H2O
   Oxygen      55.82 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca4MgAl4(PO4)6(OH)4•12(H2O)
Help on Environment: Environment: Forms a series with kingsmountainite.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1940
Help on Locality: Locality: Little Green Monster mine, Clay Canyon, Fairfield, Utah County, Utah, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Arthur Mongomery (1909-), mineralogist, teacher, collector, and founder of the Friends of Mineralogy.
Help on Name Pronunciation: Name Pronunciation: Montgomeryite + Pronunciation Say MONTGOMERYITE
Help on Synonym: Synonym: ICSD 64849
  PDF 28-225

Montgomeryite Image

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


Comments: Matrix specimen covered with sprays to 0.5 cm of salmon colored montgomeryite crystals.
Location: Tip Top Mine, Custer County, South Dakota, USA. Scale: 13 x 8 cm.
© John Veevaert

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

  Tiptopite   Montgomeryite

Comments: Clear, acicular crystals of tiptopite with red montgomeryite.
Location: Tip Top mine, Custer, Custer County, South Dakota, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

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

  Tiptopite   Englishite   Montgomeryite

Comments: Red montgomeryite lath-like crystals to 1mm in 2mm rosettes associated with clear, acicular sprays of tiptopite to 0.75mm and white cottonball-like crystals of englishite to 0.2mm.
Location: Tip Top mine, Custer Co., South Dakota, USA. Scale: Picture size 5 mm.
© Tom Loomis / Dakota Matrix

Montgomeryite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.4155:1:0.2588
Help on Cell Dimensions: Cell Dimensions: a = 10.023, b = 24.121, c = 6.243, Z = 2; beta = 91.55° V = 1,508.79 Den(Calc)= 2.52
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 5.115(1), 12.1(0.56), 2.617(0.32),

Physical Properties of Montgomeryite

Help on Cleavage: Cleavage: {010} Perfect, {100} Indistinct
Help on Color: Color: Colorless, Yellowish, White, Green, Red.
Help on Density: Density: 2.46 - 2.53, Average = 2.49
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Hardness: Hardness: 4 - Fluorite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Montgomeryite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.016 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.006 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2291,KPDmeas= 0.2314,KC= 0.2277
Ncalc = 1.56 - 1.58
Help on Optical Data: Optical Data: Biaxial (-), a=1.572, b=1.578, g=1.582, bire=0.0100, 2V(Calc)=78, 2V(Meas)=75.

Calculated Properties of Montgomeryite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.56 gm/cc
note: Specific Gravity of Montgomeryite =2.52 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0025801362
Boson Index = 0.9974198638
Help on Photoelectric: Photoelectric: PEMontgomeryite = 2.83 barns/electron
U=PEMontgomeryite x rElectron Density= 7.25 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Montgomeryite is Not Radioactive

Montgomeryite Classification

Help on  Dana Class: Dana Class: (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.11)where (AB)4 (XO4)3 Zq � x(H2O)
  (42.11.08)Montgomeryite group Montgomeryite Ca4MgAl4(PO4)6(OH)4•12(H2O) C 2/c 2/m Kingsmountite (Ca,Mn)4(Fe,Mn)Al4(PO4)6(OH)4•12(H2O) C 2 2 Calcioferrite Ca4Fe(Fe,Al)4(PO4)6(OH)4•12(H2O) C 2 2 Zodacite Ca4MnFe4(PO4)6(OH)4•12(H2O) C 2/c,Cc Mono Angastonite! CaMgAl2(PO4)2(OH)4?7H2O P1 1
Help on  Strunz Class: Strunz Class: 08.DH.25 08 - PHOSPHATES, ARSENATES, VANADATES
  08.D - Phosphates, etc
  08.DH -With large and medium-sized cations, (OH, etc.):RO4 < 1:1
08.DH.25 Calcioferrite Ca4Fe(Fe,Al)4(PO4)6(OH)4•12(H2O) C 2 2
08.DH.25 Kingsmountite (Ca,Mn)4(Fe,Mn)Al4(PO4)6(OH)4•12(H2O) C 2 2
08.DH.25 Montgomeryite Ca4MgAl4(PO4)6(OH)4•12(H2O) C 2/c 2/m
08.DH.25 Zodacite Ca4MnFe4(PO4)6(OH)4•12(H2O) C 2/c,Cc Mono

Other Montgomeryite 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 Montgomeryite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

Search for Montgomeryite using:

Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Montgomeryite :

Ask about Montgomeryite 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 Espa�ol

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


Dana No: Strunz No: 08.DH.25





Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.