Apophyllite-(KOH) Mineral Data

General Apophyllite-(KOH) Information

Chemical Formula:

KCa4Si8O20(OH,F)•8(H2O)

Composition:

Molecular Weight = 759.07 gm

Potassium 4.38 % K 5.27 % K₂O

Sodium 0.45 % Na 0.61 % Na₂O

Calcium 21.12 % Ca 29.55 % CaO

Silicon 29.60 % Si 63.32 % SiO₂

Hydrogen 0.11 % H 0.95 % H₂O

Oxygen 43.84 % O

Fluorine 0.50 % F 0.50 % F

- % F -0.21 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K_0.85Na_0.15Ca₄Si₈O₂₀(OH)_0.8F_0.2

IMA Status:

Approved IMA 1978

Locality:

Ore Knob mine, Jefferson, Ashe County, North Carolina, USA Link to MinDat.org Location Data.

Name Origin:

From the Greek apophylliso - "it flakes off" and the predominant hydroxyl anion.

Name Pronunciation:

Apophyllite-(KOH) + Pronunciation

Synonym:

Hydroxyapophyllite - Renamed to Apophyllite-(KOH) by Mineralogical Record, v39, (2008), p 131

Apophyllite-(KOH) Image

Images:

Apophyllite Apophyllite-(KOH) Stilbite-Ca

Comments: 3 cm. pink-colored rosette of stilbite and clear "apophyllite" (probably hydroxyapophyllite) in an amygdaloidal cavity.
Location: Aurangabad District, Jalgaon, India. Scale: Specimen size 6 cm.
© Dave Barthelmy

Images:

Apophyllite-(KOH) Apophyllite

Comments: Crystal cluster of tabular hydroxyapophyllite.
Location: Wessels Mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Scale: 2.5 x 2.3 cm.
© John Veevaert

Apophyllite-(KOH) Crystallography

Axial Ratios:

a:c = 1:1.76319

Cell Dimensions:

a = 8.978, c = 15.83, Z = 2; V = 1,275.97 Den(Calc)= 1.98

Crystal System:

Tetragonal - Ditetragonal Dipyramidal H-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): 3.965(1), 2.99(0.67), 1.588(0.26),

Physical Properties of Apophyllite-(KOH)

Cleavage:

{001} Perfect

Color:

White, Pink, Green, Yellow, Violet.

Density:

2.3 - 2.4, Average = 2.34

Diaphaneity:

Transparent

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-(KOH)

Gladstone-Dale:

CI meas= -0.106 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.313 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.274,KPDmeas= 0.2309,KC= 0.2087
Ncalc = 1.41 - 1.5

Optical Data:

Uniaxial (+), w=1.542, e=1.543, bire=0.0010.

Calculated Properties of Apophyllite-(KOH)

Electron Density:

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

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Apophyllite-(KOH)}= 4.17 barns/electron
U=PE_{Apophyllite-(KOH)} x r_electron= 9.78 barns/cc.

Radioactivity:

GRapi = 63.07 (Gamma Ray American Petroleum Institute Units)
Concentration of Apophyllite-(KOH) per GRapi unit = 1.59 (%)

Estimated Radioactivity from Apophyllite-(KOH) - barely detectable

Apophyllite-(KOH) Classification

Dana Class:

72.03.01.02 (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-(KOH) Information

References:

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

See Also:

Links to other databases for Apophyllite-(KOH) :
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-(KOH) Specimen Label here :

Apophyllite-(KOH)

KCa4Si8O20(OH,F)•8(H2O)
Dana No: 72.03.01.02 Strunz No: 09.EA.15
Locality:

Notes:

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