Endellite Mineral Data

General Endellite Information

Chemical Formula:

Al2Si2O5(OH)4•2(H2O)

Composition:

Molecular Weight = 294.19 gm

Aluminum 18.34 % Al 34.66 % Al₂O₃

Silicon 19.09 % Si 40.85 % SiO₂

Hydrogen 2.74 % H 24.49 % H₂O

Oxygen 59.82 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al₂Si₂O₅(OH)₄•2(H₂O)

Environment:

Formed by weathering or hydrothermal alteration of aluminosilicate minerals. Dehydrates to halloysite above 400 deg C.

IMA Status:

Discredited IMA 1967 (Dana # Added)

Locality:

North Gardiner mine, Bedford, Lawrence County, Indiana, USA. Link to MinDat.org Location Data.

Name Origin:

Named in 1943 for Kurt Endell (1887{?), German geologist, one of the discoverers of the mineral.

Synonym:

Hydrohalloysite

Kimolite

Endellite Image

Images:

Endellite

Comments: Gray to white massive endellite.
Location: Buck Reef Deposit, Ravenswood, Queensland, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Endellite Crystallography

Axial Ratios:

a:b:c =0.5775:1:2.3258

Cell Dimensions:

a = 5.14, b = 8.9, c = 20.7, Z = 4; beta = 99.7° V = 933.40 Den(Calc)= 2.09

Crystal System:

Monoclinic - Domatic H-M Symbol (m) Space Group: Cc

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

By Intensity(I/I_o): 4.42(1), 1.481(0.9), 10.1(0.9),3.34(0.9), 1.678(0.8), 2.56(0.8), 1.283(0.7),

Physical Properties of Endellite

Cleavage:

None

Color:

Blue, Brown, Colorless, Green, Gray.

Density:

2.18 - 2.3, Average = 2.24

Diaphaneity:

Transparent to Translucent

Fracture:

Earthy - Dull, clay-like fractures with no visible crystalline affinities, (e.g. howlite).

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Habit:

Porcelainous - Fine-grained, translucent massive material like broken china

Hardness:

1-2 - Between Talc and Gypsum

Luminescence:

Non-fluorescent.

Luster:

Earthy (Dull)

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Endellite

Gladstone-Dale:

CI meas= 0.001 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.071 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2569,KPDmeas= 0.2397,KC= 0.24
Ncalc = 1.5 - 1.55

Optical Data:

Biaxial (?), b=1.537

Calculated Properties of Endellite

Electron Density:

Bulk Density (Electron Density)=2.28 gm/cc
note: Specific Gravity of Endellite =2.24 gm/cc.

Fermion Index:

Fermion Index = 0.0092078686
Boson Index = 0.9907921314

Photoelectric:

PE_Endellite= 1.33 barns/electron
U=PE_Endellite x rElectron Density= 3.04 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Endellite is Not Radioactive

Endellite Classification

Dana Class:

71.01.01.04a (71)Phyllosilicate Sheets of Six-Membered Rings

(71.01)with 1:1 layers

(71.01.01)Kaolinite group

71.01.01.01 Dickite Al2Si2O5(OH)4 Cc m

71.01.01.02 Kaolinite Al2Si2O5(OH)4 P1 1

71.01.01.03 Nacrite Al2Si2O5(OH)4 Cc m

71.01.01.04 Halloysite Al2Si2O5(OH)4 Cc m

71.01.01.04a Endellite? Al2Si2O5(OH)4•2(H2O) Cc m

71.01.01.05 Odinite (Fe,Mg,Al,Fe,Ti,Mn)2.5(Si,Al)2O5(OH)4 Cm m

Strunz Class:

09.ED.10 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.ED -Phyllosilicates with kaolinite layers

09.ED.10 Endellite! Al2Si2O5(OH)4•2(H2O) Cc m

09.ED.10 Hisingerite Fe2Si2O5(OH)4•2(H2O) Unk Mono

09.ED.10 Halloysite Al2Si2O5(OH)4 Cc m

09.ED.10 Sturtite? (Fe3)(Mn2,Ca,Mg)Si4O10(OH)3•10(H2O) None

Other Endellite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Endellite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (UofA)
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info

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

Endellite

Al2Si2O5(OH)4•2(H2O)
Dana No: 71.01.01.04a Strunz No: 09.ED.10
Locality:

Notes:

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