Hillite Mineral Data

General Hillite Information

Chemical Formula:

Ca2(Zn, Mg)[PO4]2•2(H2O)

Composition:

Molecular Weight = 356.69 gm

Sodium 0.06 % Na 0.09 % Na₂O

Calcium 21.46 % Ca 30.03 % CaO

Magnesium 2.59 % Mg 4.29 % MgO

Zinc 11.73 % Zn 14.60 % ZnO

Phosphorus 17.63 % P 40.39 % P₂O₅

Hydrogen 1.13 % H 10.10 % H₂O

Oxygen 45.39 % O

______ ______

100.00 % 99.51 % = TOTAL OXIDE

Empirical Formula:

Ca_1.91Na_0.01Zn_0.64Mg_0.38(PO₄)_2.03•2(H₂O)

Environment:

Secondary mineral in a gossan on poorly-sorted argillacous siltstones. Zn-dominant analogue of collinsite

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Lower Cambrian Parachlna Formation, Reaphook Hill, South Australia. Link to MinDat.org Location Data.

Name Origin:

Named for Roderik Hill (1949-), Chief of Mineral Research Division, CSIRO, Melbourne, Autralia.

Synonym:

Collinsite-Zn

IMA2003-005

Hillite Image

Images:

Hillite Scholzite

Comments: Morphology of a homogeneous larger cluster of hillite growing on an acicular crystal of scholzite. SEM back-scattered electron image.
Location: Lower Cambrian Parachilna Formation, Reaphook Hill, South Australia, Australia. Scale: See Image.
© Canadian Mineralogist

Hillite Crystallography

Axial Ratios:

a:b:c =0.8476:1:0.8071

Cell Dimensions:

a = 5.736, b = 6.767, c = 5.462, Z = 1; alpha = 97.41°, beta = 108.59°, gamma = 107.19° V = 190.37 Den(Calc)= 3.11

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 2.69(1)(100), 3.038(0.4)(101), 3.13(0.37)(020),6.24(0.34)(010), 1.668(0.22), 3.23(0.22)(110), 2.23(0.14)(130),

Physical Properties of Hillite

Cleavage:

{010} Perfect, {001} Perfect

Color:

Colorless, Gray, Greenish gray, Bluish gray.

Density:

3.16

Diaphaneity:

Transparent

Habit:

Blocky - Crystal shape tends to be equant (e.g. feldspars).

Hardness:

3.5 - Copper Penny

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Hillite

Gladstone-Dale:

CI meas= -0.015 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.008 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2048,KPDmeas= 0.2061,KC= 0.2031
Ncalc = 1.64 - 1.65

Optical Data:

Biaxial (+), a=1.635, b=1.65, g=1.669, bire=0.0340

Calculated Properties of Hillite

Electron Density:

Bulk Density (Electron Density)=3.16 gm/cc
note: Specific Gravity of Hillite =3.18 gm/cc.

Fermion Index:

Fermion Index = 0.0079091465
Boson Index = 0.9920908535

Photoelectric:

PE_Hillite= 9.21 barns/electron
U=PE_Hillite x rElectron Density= 29.13 barns/cc.

Radioactivity:

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

Hillite Classification

Dana Class:

40.02.02.09 (40)Hydrated Phosphates, etc

(40.02)where A++ (B++)2 (XO4) ï¿½ x(H2O)

(40.02.02)Fairfieldite Subgroup (Triclinic: P-1ï¿½)

40.02.02.01 Fairfieldite Ca2(Mn,Fe)(PO4)2•2(H2O) P1 1

40.02.02.02 Messelite Ca2(Fe,Mn)(PO4)2•2(H2O) P1 1

40.02.02.03 Collinsite Ca2(Mg,Fe)(PO4)2•2(H2O) P1 1

40.02.02.04 Cassidyite Ca2(Ni,Mg)(PO4)2•2(H2O) P1 1

40.02.02.05 Talmessite Ca2Mg(AsO4)2•2(H2O) P1 1

40.02.02.06 Gaitite Ca2Zn(AsO4)2•2(H2O) P1 1

40.02.02.07 Roselite-beta Ca2(Co,Mg)(AsO4)2•2(H2O) P 1 or P1 Tri

40.02.02.08 Parabrandtite Ca2Mn(AsO4)•2(H2O) P1,P 1 Tri

40.02.02.09 Hillite! Ca2(Zn,Mg)[PO4]2•2(H2O) P1 1

40.02.02.10 Nickeltalmessite! Ca2Ni(AsO4)2•2H2O P 1

Strunz Class:

08.CG.05 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CG -With large and medium-sized cations, RO4:H2O = 1:1

08.CG.05 Collinsite Ca2(Mg,Fe)(PO4)2•2(H2O) P1 1

08.CG.05 Gaitite Ca2Zn(AsO4)2•2(H2O) P1 1

08.CG.05 Cassidyite Ca2(Ni,Mg)(PO4)2•2(H2O) P1 1

08.CG.05 Fairfieldite Ca2(Mn,Fe)(PO4)2•2(H2O) P1 1

08.CG.05 Messelite Ca2(Fe,Mn)(PO4)2•2(H2O) P1 1

08.CG.05 Parabrandtite Ca2Mn(AsO4)•2(H2O) P1,P 1 Tri

08.CG.05 Uranophane-beta Ca[(UO2)SiO3(OH)]2•(H2O) P 2₁/a 2/m

08.CG.05 Talmessite Ca2Mg(AsO4)2•2(H2O) P1 1

08.CG.05 Hillite! Ca2(Zn,Mg)[PO4]2•2(H2O) P1 1

Other Hillite Information

References:

NAME( CanMin, 41:982) PHYS. PROP.(CanMin, 41:982) OPTIC PROP.(CanMin, 41:982)

See Also:

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

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

Hillite

Ca2(Zn, Mg)[PO4]2•2(H2O)
Dana No: 40.02.02.09 Strunz No: 08.CG.05
Locality:

Notes:

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