Variscite Mineral Data

General Variscite Information

Chemical Formula:

AlPO4•2(H2O)

Composition:

Molecular Weight = 157.98 gm

Aluminum 17.08 % Al 32.27 % Al₂O₃

Phosphorus 19.61 % P 44.92 % P₂O₅

Hydrogen 2.55 % H 22.81 % H₂O

Oxygen 60.76 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al(PO₄)•2(H₂O)

Environment:

High-phosphate, meteoric waters acting on aluminous rocks.

IMA Status:

Valid Species (Pre-IMA) 1837

Locality:

Messbach, Plauen, Vogtland (Variscia), Thuringen, Germany Link to MinDat.org Location Data.

Name Origin:

Named after Variscia, the historical name of Vogtland, Germany.

Name Pronunciation:

Variscite + Pronunciation

Synonym:

Barrandite

Bolivarite

Coeruleolactite - mixture of planerite + variscite + wavellite

Lucinite

Utahlite

Variscite Image

Images:

Variscite

Comments: Polished slice of lime green variscite.
Location: Fairfield, Utah. USA. Scale: 5.5 x 8.5 cm x 3 mm.
© Dan Weinrich

Images:

Variscite

Comments: Deep rasberry red drusy micro crystals of variscite in vuggy matrix.
Location: Iron Monarch quarry, Iron Knob, South Australia, Australia. Scale: Picture size 1 cm.
© Tom Loomis / Dakota Matrix

Images:

Variscite

Comments: Brilliant cherry red well-defined, clusters of variscite crystals forming tiny single spheroids on white quartz.
Location: Boa Vista, Galileia, Minas Gerais, Brazil. Scale: Sphere size 0.3 mm.
© Tom Loomis / Dakota Matrix

Variscite Crystallography

Axial Ratios:

a:b:c =1.0248:1:1.7784

Cell Dimensions:

a = 9.9, b = 9.66, c = 17.18, Z = 16; V = 1,642.99 Den(Calc)= 2.55

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pcab

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

By Intensity(I/I_o): 4.29(1), 5.39(0.6), 4.83(0.45),

Physical Properties of Variscite

Cleavage:

{010} Perfect

Color:

Blue green, Colorless, Green, Light green.

Density:

2.5 - 2.52, Average = 2.5

Diaphaneity:

Transparent to Translucent

Fracture:

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

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

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

Hardness:

4-5 - Fluorite-Apatite

Luminescence:

Fluorescent, Long UV=grass green.

Luster:

Earthy (Dull)

Streak:

white

Optical Properties of Variscite

Gladstone-Dale:

CI meas= -0.023 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.007 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2281,KPDmeas= 0.2317,KC= 0.2266
Ncalc = 1.57 - 1.58

Optical Data:

Biaxial (-), a=1.563, b=1.588, g=1.594, bire=0.0310, 2V(Calc)=50, 2V(Meas)=moderate. Dispersion r < v weak.

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Variscite

Electron Density:

Bulk Density (Electron Density)=2.58 gm/cc
note: Specific Gravity of Variscite =2.55 gm/cc.

Fermion Index:

Fermion Index = 0.0002954932
Boson Index = 0.9997045068

Photoelectric:

PE_Variscite= 1.49 barns/electron
U=PE_Variscite x rElectron Density= 3.84 barns/cc.

Radioactivity:

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

Variscite Classification

Dana Class:

40.04.01.01 (40)Hydrated Phosphates, etc

(40.04)where A+++ XO4 ï¿½ x(H2O)

(40.04.01)Variscite Group

40.04.01.01 Variscite AlPO4•2(H2O) Pcab 2/m 2/m 2/m

40.04.01.02 Strengite FePO4•2(H2O) Pcab 2/m 2/m 2/m

40.04.01.03 Scorodite FeAsO4•2(H2O) Pcab 2/m 2/m 2/m

40.04.01.04 Mansfieldite AlAsO4•2(H2O) Pcab 2/m 2/m 2/m

40.04.01.05 Yanomamite In(AsO4)•2(H2O) P bca 2/m 2/m 2/m

Strunz Class:

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

08.C - Phosphates without Additional Anions, with H2O

08.CD -With only medium-sized cations, RO4:H2O = 1:2

08.CD.10 Strengite FePO4•2(H2O) Pcab 2/m 2/m 2/m

08.CD.10 Mansfieldite AlAsO4•2(H2O) Pcab 2/m 2/m 2/m

08.CD.10 Variscite AlPO4•2(H2O) Pcab 2/m 2/m 2/m

08.CD.10 Scorodite FeAsO4•2(H2O) Pcab 2/m 2/m 2/m

08.CD.10 Yanomamite In(AsO4)•2(H2O) P bca 2/m 2/m 2/m

Other Variscite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Collectors Book of Fluorescent Minerals) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

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

Variscite

AlPO4•2(H2O)
Dana No: 40.04.01.01 Strunz No: 08.CD.10
Locality:

Notes:

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