Evansite Mineral Data

General Evansite Information

Chemical Formula:

Al3(PO4)(OH)6•6(H2O) (?)

Composition:

Molecular Weight = 386.05 gm

Aluminum 20.97 % Al 39.62 % Al₂O₃

Phosphorus 8.02 % P 18.38 % P₂O₅

Hydrogen 4.70 % H 42.00 % H₂O

Oxygen 66.31 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al₃(PO₄)(OH)₆•6(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1864

Locality:

Zeleznï¿½k Mt, Sirk, Slovakia Link to MinDat.org Location Data.

Name Origin:

Named after the English metallurgist, Brooke Evans (1797-1862),

Name Pronunciation:

Evansite

Evansite Image

Images:

Evansite

Comments: Cream-colored, amorphous evansite coating an unknown striated, prismatic mineral, now missing (see hollow shells)..
Location: Cobalt, Idaho. Scale: Picture size 3 cm.
© John Veevaert

Evansite Crystallography

Crystal System:

Amorphous- No Crystals

Physical Properties of Evansite

Cleavage:

None

Color:

Colorless, White, Yellow, Green, Blue.

Density:

1.9 - 2, Average = 1.95

Diaphaneity:

Transparent to translucent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Botryoidal - "Grape-like" rounded forms (e.g.. malachite).

Habit:

Reniform - "Kidney like" in shape (e.g.. hematite).

Habit:

Stalactitic - Shaped like pendant columns as stalactites or stalagmites (e.g. calcite).

Hardness:

3.5-4 - Copper Penny-Fluorite

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Pearly

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Evansite

Gladstone-Dale:

CI meas= 0.038 (Excellent) - where the CI = (1-KPDmeas/KC)
KPDmeas= 0.2487,KC= 0.2584
Ncalc = 1.49 - 1.52

Optical Data:

Isotropic, n=1.485.

Calculated Properties of Evansite

Electron Density:

Bulk Density (Electron Density)=2.02 gm/cc
note: Specific Gravity of Evansite =1.95 gm/cc.

Fermion Index:

Fermion Index = 0.0003253368
Boson Index = 0.9996746632

Photoelectric:

PE_Evansite= 1.11 barns/electron
U=PE_Evansite x rElectron Density= 2.23 barns/cc.

Radioactivity:

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

Evansite Classification

Dana Class:

42.01.02.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.01)where (A)3 (XO4) Zq ï¿½ x(H2O)

(42.01.02)Dana Group

42.01.02.01 Evansite Al3(PO4)(OH)6•6(H2O)(?) None

Strunz Class:

08.DF.10 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DF -With only medium-sized cations, (OH,etc.):RO4 > 3:1

08.DF.10 Bolivarite Al2(PO4)(OH)3•4-5(H2O) None

08.DF.10 Evansite Al3(PO4)(OH)6•6(H2O)(?) None

08.DF.10 Liskeardite (Al,Fe)3(AsO4)(OH)6•5(H2O) Unk Ortho

08.DF.10 Rosieresite (Pb,Cu,Al)(PO4)x•n(H2O) None

Other Evansite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Duda&Rejl90) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Evansite :
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

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

Evansite

Al3(PO4)(OH)6•6(H2O) (?)
Dana No: 42.01.02.01 Strunz No: 08.DF.10
Locality:

Notes:

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