Apophyllite-(KF) Mineral Data

General Apophyllite-(KF) Information

Chemical Formula:

(K,Na)Ca4Si8O20(F,OH)•8(H2O)

Composition:

Molecular Weight = 760.47 gm

Potassium 4.37 % K 5.26 % K₂O

Sodium 0.45 % Na 0.61 % Na₂O

Calcium 21.08 % Ca 29.50 % CaO

Silicon 29.55 % Si 63.21 % SiO₂

Hydrogen 0.01 % H 0.12 % H₂O

Oxygen 42.29 % O

Fluorine 2.25 % F 2.25 % F

- % F -0.95 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K_0.85Na_0.15Ca₄Si₈O₂₀F_0.9(OH)_0.1

Environment:

A secondary mineral in amygdules or druses in basalts. A late-stage mineral in some mineral deposits.

IMA Status:

Approved IMA 1978

Locality:

Poona, Nasik, and Bombay districts, Maharashtra, India. Link to MinDat.org Location Data.

Name Origin:

From the Greek apophylliso - "it flakes off." and the composition containing fluorine;

Name Pronunciation:

Apophyllite-(KF) + Pronunciation

Synonym:

Fluorapophyllite - Renamed to Apophyllite-(F) by Mineralogical Record, v39, (2008), p 131

Apophyllite-(KF) Image

Images:

Click Here for Larger Apophyllite-(KF) Image

Apophyllite-(KF) Stilbite-Ca Apophyllite

Comments: Doubly terminated, very clear and perfect fluorapophyllite with white stilbite.
Location: Jalgaon, India. Scale: 4 x 3.5 cm.
© Fabre Minerals

Apophyllite-(KF) Crystallography

Axial Ratios:

a:c = 1:1.76324

Cell Dimensions:

a = 8.963, c = 15.804, Z = 2; V = 1,269.62 Den(Calc)= 1.99

Crystal System:

Tetragonal - Ditetragonal DipyramidalH-M Symbol (4/m 2/m 2/m) Space Group: P 4/mnc

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

By Intensity(I/I_o): 7.81(1), 2.49(0.9), 3.57(0.6),2.95(0.5), 3.9(0.5), 4.51(0.45), 3.17(0.4),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Stahl K , European Journal of Mineralogy , 5 (1993) p.845-849, A neutron powder diffraction study of partially dehydrated, fluorapophyllite, KCa4Si8O20F*6.9H2O

Physical Properties of Apophyllite-(KF)

Cleavage:

{001} Perfect

Color:

White, Pink, Green, Yellow, Violet.

Density:

2.3 - 2.4, Average = 2.34

Diaphaneity:

Transparent to Translucent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Crystalline - Coarse - Occurs as well-formed coarse sized crystals.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

Pseudo Cubic - Crystals show a cubic outline.

Hardness:

4-5 - Fluorite-Apatite

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Apophyllite-(KF)

Gladstone-Dale:

CI meas= -0.101 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.3 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2683,KPDmeas= 0.2272,KC= 0.2064
Ncalc = 1.41 - 1.5

Optical Data:

Uniaxial (+), w=1.53-1.536, e=1.532-1.538, bire=0.0020.

Calculated Properties of Apophyllite-(KF)

Electron Density:

Bulk Density (Electron Density)=2.34 gm/cc
note: Specific Gravity of Apophyllite-(KF) =2.35 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Apophyllite-(KF)}= 4.17 barns/electron
U=PE_{Apophyllite-(KF)} x r_electron= 9.77 barns/cc.

Radioactivity:

GRapi = 62.81 (Gamma Ray American Petroleum Institute Units)
Concentration of Apophyllite-(KF) per GRapi unit = 1.59 (%)

Estimated Radioactivity from Apophyllite-(KF) - barely detectable

Apophyllite-(KF) Classification

Dana Class:

72.03.01.01 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings

(72.03)with 3-, 4-, or 5-membered rings and 8-membered rings

(72.03.01)Apophyllite group (4- & 8-membered rings)

72.03.01.00 Apophyllite* KCa4(Si4O10)2F•8(H2O) P 4/mnc 4/m 2/m 2/m

72.03.01.01 Apophyllite-(KF) (K,Na)Ca4Si8O20(F,OH)•8(H2O) P 4/mnc 4/m 2/m 2/m

72.03.01.02 Apophyllite-(KOH) KCa4Si8O20(OH,F)•8(H2O) P 4/mnc 4/m 2/m 2/m

72.03.01.03 Apophyllite-(NaF) NaCa4Si8O20F•8(H2O) Pnnm 2/m 2/m 2/m

72.03.01.04 Carletonite KNa4Ca4Si8O18(CO3)4(OH,F)•(H2O) P 4/mbm 4/m 2/m 2/m

Strunz Class:

09.EA.15 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EA -Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings

09.EA.15 Apophyllite* KCa4(Si4O10)2F•8(H2O) P 4/mnc 4/m 2/m 2/m

09.EA.15 Apophyllite-(KOH) KCa4Si8O20(OH,F)•8(H2O) P 4/mnc 4/m 2/m 2/m

09.EA.15 Apophyllite-(KF) (K,Na)Ca4Si8O20(F,OH)•8(H2O) P 4/mnc 4/m 2/m 2/m

09.EA.15 Apophyllite-(NaF) NaCa4Si8O20F•8(H2O) Pnnm 2/m 2/m 2/m

Other Apophyllite-(KF) Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)

See Also:

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

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Print or Cut-and-Paste your Apophyllite-(KF) Specimen Label here :

Apophyllite-(KF)

(K,Na)Ca4Si8O20(F,OH)•8(H2O)
Dana No: 72.03.01.01 Strunz No: 09.EA.15
Locality:

Notes: