Fluorapophyllite-(NH4)
A valid IMA mineral species - pending publication
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About Fluorapophyllite-(NH4)
Formula:
NH4Ca4(Si8O20)F · 8H2O
Colour:
Colourless to light pink
Lustre:
Vitreous, Pearly
Hardness:
4½ - 5
Specific Gravity:
2.325 (Calculated)
Crystal System:
Tetragonal
Member of:
Name:
Named for being the ammonium (NH4) analogue of fluorapophyllite-(K).
Ammonium dominant fluorapophyllite. The NH4 analogue of fluorapophyllite-(K).
Unique combination of elements.
First group member with essential ammonium.
Unique combination of elements.
First group member with essential ammonium.
Name Encoding
Formatted:
fluorapophyllite-(NH4)
HTML:
fluorapophyllite-(NH<sub>4</sub>)
LaTeX:
fluorapophyllite-(NH\$\_4\$)
Unique Identifiers
Mindat ID:
53993
Long-form identifier:
mindat:1:1:53993:3
Similar Names
| Fluorapophyllite | A synonym | |
| Fluorapophyllite-(Cs) | A valid IMA mineral species | CsCa4(Si8O20)F · 8H2O |
| Fluorapophyllite-(K) | A valid IMA mineral species - grandfathered | KCa4(Si8O20)(F,OH) · 8H2O |
| Fluorapophyllite-(K) - Hydroxyapophyllite-(K) Series | A solid-solution series between two end-member minerals | |
| Fluorapophyllite-(Na) | A valid IMA mineral species | NaCa4(Si8O20)F · 8H2O |
IMA Classification of Fluorapophyllite-(NH4)
Approved, Pending publication
IMA Formula:
(NH4)Ca4(Si8O20)F · 8H2O
Approval year:
2019
First published:
2020
Classification of Fluorapophyllite-(NH4)
9.EA.
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Fapo-NH4 | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Fapo | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Fluorapophyllite-(NH4)
Vitreous, Pearly
Transparency:
Transparent
Colour:
Colourless to light pink
Streak:
White
Hardness:
4½ - 5 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
On {001}
On {001}
Fracture:
Irregular/Uneven
Density:
2.325 g/cm3 (Calculated)
Optical Data of Fluorapophyllite-(NH4)
Type:
Uniaxial (+)
RI values:
nω = 1.5414(5) nε = 1.5393(8)
Max. Birefringence:
δ = 0.002
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
None to Very Low
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Pleochroism:
Non-pleochroic
Chemistry of Fluorapophyllite-(NH4)
Mindat Formula:
NH4Ca4(Si8O20)F · 8H2O
Element Weights:
Crystallography of Fluorapophyllite-(NH4)
Crystal System:
Tetragonal
Class (H-M):
4/mmm(4/m2/m2/m) - Ditetragonal Dipyramidal
Space Group:
P4/mnc
Cell Parameters:
a = 8.99336(9) Å, c = 15.7910(3) Å
Ratio:
a:c = 1 : 1.756
Unit Cell V:
1277.18 ų
Z:
2
Morphology:
Forms {110}, {101} and {001}
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.897 Å | (31) |
| 7.812 Å | (13) |
| 4.547 Å | (14) |
| 3.946 Å | (100) |
| 2.985 Å | (39) |
| 2.484 Å | (11) |
| 2.010 Å | (10) |
| 1.579 Å | (12) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4a: Earth’s earliest continental crust | >4.4-3.0 |
| 20 : Acidic volcanic rocks |
Type Occurrence of Fluorapophyllite-(NH4)
General Appearance of Type Material:
Clusters, aggregates or crystalline crusts consisting of individual, well-developed crystals up to 4 mm in size
Place of Conservation of Type Material:
In the collections of the Department of Mineralogy and Petrology, National Museum in Prague, Cirkusová 1740, 19300 Prague 9, Czech Republic, catalogue number P1P 44/2019
Geological Setting of Type Material:
In cavities of quartz–illite–saponite–tobelite xenolith embedded in pyroxene andesite
Associated Minerals at Type Locality:
Synonyms of Fluorapophyllite-(NH4)
Other Language Names for Fluorapophyllite-(NH4)
Relationship of Fluorapophyllite-(NH4) to other Species
Member of:
Other Members of Apophyllite Group:
| Fluorapophyllite-(Cs) | CsCa4(Si8O20)F · 8H2O | Tet. |
| Fluorapophyllite-(K) | KCa4(Si8O20)(F,OH) · 8H2O | Tet. 4/mmm(4/m2/m2/m) : P4/mnc |
| Fluorapophyllite-(Na) | NaCa4(Si8O20)F · 8H2O | Orth. |
| Hydroxyapophyllite-(K) | KCa4(Si8O20)(OH,F) · 8H2O | Tet. 4/mmm(4/m2/m2/m) |
| Hydroxyapophyllite-(NH4) | (NH4)Ca4(Si8O20)(OH)(H2O)8 | Tet. 4/mmm(4/m2/m2/m) |
| Hydroxymcglassonite-(K) | KSr4Si8O20(OH) · 8H2O | Tet. |
Common Associates
Related Minerals - Strunz-mindat Grouping
| 9.EA. | Hydroxymcglassonite-(K) | KSr4Si8O20(OH) · 8H2O |
| 9.EA. | Miyawakiite-(Y) | ◻Y4Fe2(Si8O20)(CO3)4(H2O)3 |
| 9.EA. | Bussyite-(Y) | (Y,REE,Ca)3(Na,Ca)6MnSi9Be5(O,OH,F)34 |
| 9.EA. | Hydroxyapophyllite-(NH4) | (NH4)Ca4(Si8O20)(OH)(H2O)8 |
| 9.EA.05 | Gillespite | BaFe2+Si4O10 |
| 9.EA.05 | Cuprorivaite | CaCuSi4O10 |
| 9.EA.05 | Wesselsite | SrCuSi4O10 |
| 9.EA.05 | Effenbergerite | BaCuSi4O10 |
| 9.EA.07 | Fluorapophyllite-(Cs) | CsCa4(Si8O20)F · 8H2O |
| 9.EA.10 | Ekanite | Ca2ThSi8O20 |
| 9.EA.15 | Fluorapophyllite-(Na) | NaCa4(Si8O20)F · 8H2O |
| 9.EA.15 | Fluorapophyllite-(K) | KCa4(Si8O20)(F,OH) · 8H2O |
| 9.EA.15 | Hydroxyapophyllite-(K) | KCa4(Si8O20)(OH,F) · 8H2O |
| 9.EA.20 | Magadiite | Na2Si14O29 · 11H2O |
| 9.EA.25 | Dalyite | K2ZrSi6O15 |
| 9.EA.25 | Davanite | K2TiSi6O15 |
| 9.EA.30 | Sazhinite-(La) | Na3La[Si6O15] · 2H2O |
| 9.EA.30 | Sazhinite-(Ce) | Na3CeSi6O15 · 2H2O |
| 9.EA.35 | Armstrongite | CaZr[Si6O15] · 3H2O |
| 9.EA.40 | Okenite | Ca10Si18O46 · 18H2O |
| 9.EA.45 | Perettiite-(Y) | Y2Mn4FeSi2B8O24 |
| 9.EA.45 | Nekoite | Ca3Si6O15 · 7H2O |
| 9.EA.45 | Badakhshanite-(Y) | Y2Mn4Al(Si2B7BeO24) |
| 9.EA.47 | Shlykovite | KCa[Si4O9(OH)] · 3H2O |
| 9.EA.50 | Diegogattaite | Na2CaCu2Si8O20 · H2O |
| 9.EA.50 | Cavansite | Ca(VO)Si4O10 · 4H2O |
| 9.EA.52 | Yangite | PbMnSi3O8 · H2O |
| 9.EA.55 | Pentagonite | Ca(VO)Si4O10 · 4H2O |
| 9.EA.60 | Penkvilksite | Na4Ti2Si8O22 · 4H2O |
| 9.EA.60 | Tumchaite | Na2Zr(Si4O11) · 2H2O |
| 9.EA.65 | Nabesite | Na2BeSi4O10 · 4H2O |
| 9.EA.70 | Ajoite | (K,Na)Cu7AlSi9O24(OH)6 · 3H2O |
| 9.EA.75 | Zeravshanite | Na2Cs4Zr3[Si18O45]*2H2O |
| 9.EA.80 | Bussyite-(Ce) | (Ce,REE)3(Na,H2O)6MnSi9Be5(O,OH)30F4 |
| 9.EA.85 | Plumbophyllite | Pb2Si4O10 · H2O |
Fluorescence of Fluorapophyllite-(NH4)
Not fluorescent
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Fluorapophyllite-(NH4)
mindat.org URL:
https://www.mindat.org/min-53993.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Fluorapophyllite-(NH4)
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2020) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 53. European Journal of Mineralogy, 32 (1) 209-213 doi:10.5194/ejm-32-209-2020
Localities for Fluorapophyllite-(NH4)
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Slovakia (TL) | |
| Števko et al. (2020) |
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Vechec quarry, Vechec, Vranov nad Topľou District, Prešov Region, Slovakia