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 % Al₂O₃

Hydrogen 3.00 % H 26.80 % H₂O

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(H₂O)

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

Comments: Pinkish-white globular aggregates of alumohydrocalcite.
Location: Carriere de Richelle, Vise, Belgium. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

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

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 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:

PE_{Alumohydrocalcite}= 2.07 barns/electron
U=PE_{Alumohydrocalcite} x rElectron 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 ï¿½ 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 Español

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.