Alumohydrocalcite Mineral Data
General Alumohydrocalcite Information
Chemical Formula:
CaAl2(CO3)2(OH)4•3(H2O)
Composition:
Molecular Weight = 336.13 gm
Calcium 11.92 % Ca 16.68 % CaO
Aluminum 16.05 % Al 30.33 % Al2 O3
Hydrogen 3.00 % H 26.80 % H2 O
Carbon 7.15 % C 26.19 % CO2
Oxygen 61.88 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
CaAl2 (CO3 )2 (OH)4 •3(H2 O)
Environment:
Secondary mineral associated with allophane.
IMA Status:
Valid Species (Pre-IMA) 1926
Locality:
Khakassky district, Russia. Link to MinDat.org Location Data.
Name Origin:
Named after its chemical composition.
Name Pronunciation:
Alumohydrocalcite
Alumohydrocalcite Image
Images:
Alumohydrocalcite Crystallography
Axial Ratios:
a:b:c =0.4494:1:0.3927
Cell Dimensions:
a = 6.498, b = 14.457, c = 5.678, Z = 2; alpha = 95.83°, beta = 93.23°, gamma = 82.24° V = 524.95 Den(Calc)= 2.13
Crystal System:
Triclinic - Pinacoidal H-M Symbol ( 1 ) Space Group: P1
X Ray Diffraction:
By Intensity(I/Io ): 6.25(1), 6.5(0.7), 3.23(0.6),
Physical Properties of Alumohydrocalcite
Cleavage:
{100} Perfect, {010} Imperfect
Color:
Chalky white, Bluish white, Violet, Light yellow, Gray.
Density:
2.23
Diaphaneity:
Transparent to subtranslucent
Fracture:
Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habit:
Acicular - Occurs as needle-like crystals.
Habit:
Massive - Fibrous - Distinctly fibrous fine-grained forms.
Habit:
Spherical - Spherical, rounded aggregates.
Hardness:
2.5 - Finger Nail
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Alumohydrocalcite
Gladstone-Dale:
CI meas = 0.003 (Superior) - where the CI = (1-KPDmeas /KC ) CI calc = -0.044 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2549,KPDmeas = 0.2434,KC = 0.2442 Ncalc = 1.52 - 1.54
Optical Data:
Biaxial (-), a=1.485-1.502, b=1.553-1.562, g=1.57-1.585, bire=0.0830-0.0850, 2V(Calc)=50-60, 2V(Meas)=64.
Calculated Properties of Alumohydrocalcite
Electron Density:
Bulk Density (Electron Density)=2.28 gm/cc note: Specific Gravity of Alumohydrocalcite =2.23 gm/cc.
Fermion Index:
Fermion Index = 0.0012485932 Boson Index = 0.9987514068
Photoelectric:
PEAlumohydrocalcite = 2.07 barns/electronU=PEAlumohydrocalcite x r Electron Density= 4.73 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Alumohydrocalcite is Not Radioactive
Alumohydrocalcite Classification
Dana Class:
16b.02.03.01 (16b) Carbonates - Hydroxyl or Halogen
(16b.02) where (A)m (B)n (XO3)p Zq � x(H2O), with (m+n):p=3:2
(16b.02.03) Dana Group
16b.02.03.01 Alumohydrocalcite CaAl2(CO3)2(OH)4•3(H2O) P1 1
16b.02.03.02 Para-alumohydrocalcite CaAl2(CO3)2(OH)4•6(H2O) Tri
Strunz Class:
05.DB.05 05 - CARBONATES (NITRATES)
05.D - Carbonates with Additional Anions, with H2O
05.DB -With large and medium-sized cations
05.DB.05 Alumohydrocalcite CaAl2(CO3)2(OH)4•3(H2O) P1 1
05.DB.05 Nasledovite PbMn3Al4(CO3)4(SO4)O5•5(H2O) Tri
05.DB.05 Para-alumohydrocalcite CaAl2(CO3)2(OH)4•6(H2O) Tri
Other Alumohydrocalcite Information
References:
NAME( Duda&Rejl90) PHYS. PROP.(Dana8) OPTIC PROP.(Ford32)
See Also:
Links to other databases for Alumohydrocalcite :
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 Alumohydrocalcite using:
[AOL ]
[Bing ]
[Dog Pile ]
[GeoScienceWorld ]
[HotBot ]
[Ixquick ]
[Lycos ]
[MAMMA ]
[Scirus ]
[Teoma ]
[WebCrawler ]
[Wikipedia ]
[YAHOO ]
Visit our Advertisers for Alumohydrocalcite :
Ask about Alumohydrocalcite 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 Alumohydrocalcite Specimen Label here :
Alumohydrocalcite
CaAl2(CO3)2(OH)4•3(H2O)
Dana No: 16b.02.03.01 Strunz No: 05.DB.05
Locality:
Notes:
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.