Magnesiotaaffeite-2N’2S
A valid IMA mineral species - grandfathered
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About Magnesiotaaffeite-2N’2S
Formula:
Mg3Al8BeO16
Colour:
White, green
Lustre:
Vitreous
Hardness:
8 - 8½
Specific Gravity:
3.605
Crystal System:
Hexagonal
Member of:
Name:
Named taaffeite in honor of Count Edward Charles Richard Taaffe, gemologist of Dublin (1898, Bohemia, Austria-Hungary - 1967, Dublin, Ireland), who discovered the mineral in 1945. It was the first case of a new mineral discovered as a facetted gem. The suffix was added by Armbruster et al. (2002) to indicate the polysome.
Taaffeite Group.
The stacking of the spinel-type (Mg2Al4O8) and nolanite-type (BeMgAl4O8) modules is N'SN'S. Malcherek & Schlüter (2016) describe a new polytype of the mineral, Magnesiotaaffeite-2N’2S2, with N'SSN'' stacking sequence; this new polytype crystallizes in the trigonal system, space group P-3m1; it is Cr-bearing.
Visit gemdat.org for gemological information about Magnesiotaaffeite-2N’2S.
The stacking of the spinel-type (Mg2Al4O8) and nolanite-type (BeMgAl4O8) modules is N'SN'S. Malcherek & Schlüter (2016) describe a new polytype of the mineral, Magnesiotaaffeite-2N’2S2, with N'SSN'' stacking sequence; this new polytype crystallizes in the trigonal system, space group P-3m1; it is Cr-bearing.
Visit gemdat.org for gemological information about Magnesiotaaffeite-2N’2S.Name Encoding
Formatted:
magnesiotaaffeite-2N’2S
HTML:
magnesiotaaffeite-2<i>N</i>’2<i>S</i>
LaTeX:
magnesiotaaffeite-2\textit{N}’2\textit{S}
Latin-1:
Magnesiotaaffeite-2N'2S
ASCII-7:
Magnesiotaaffeite-2N'2S
Unique Identifiers
Mindat ID:
3863
Long-form identifier:
mindat:1:1:3863:4
Similar Names
| Magnesiotaaffeite-2N’2S2 | Mg3BeAl8O16 | |
| Magnesiotaaffeite-6N’3S | A valid IMA mineral species | Mg2BeAl6O12 |
IMA Classification of Magnesiotaaffeite-2N’2S
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mg3BeAl8O16
Classification of Magnesiotaaffeite-2N’2S
4.FC.25
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
C : Hydroxides with OH, without H2O; corner-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
C : Hydroxides with OH, without H2O; corner-sharing octahedra
7.2.11.1
7 : MULTIPLE OXIDES
2 : AB2X4
7 : MULTIPLE OXIDES
2 : AB2X4
7.4.5
7 : Oxides and Hydroxides
4 : Oxides of Be, Mg and the alkaline earths
7 : Oxides and Hydroxides
4 : Oxides of Be, Mg and the alkaline earths
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 |
|---|---|---|
| Mtf-2N'2S | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Mta | 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 Magnesiotaaffeite-2N’2S
Vitreous
Transparency:
Transparent
Colour:
White, green
Streak:
White
Hardness:
8 - 8½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Imperfect/Fair
Fair {001}
Fair {001}
Fracture:
Conchoidal, Sub-Conchoidal
Density:
3.605 g/cm3 (Measured)
Optical Data of Magnesiotaaffeite-2N’2S
Type:
Uniaxial (+)
RI values:
nω = 1.722 nε = 1.777
Birefringence:
0.05
Max. Birefringence:
δ = 0.055
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:
Very High (positive)
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.
Chemistry of Magnesiotaaffeite-2N’2S
Mindat Formula:
Mg3Al8BeO16
Element Weights:
Elements listed:
Crystallography of Magnesiotaaffeite-2N’2S
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Cell Parameters:
a = 5.68 Å, c = 18.33 Å
Ratio:
a:c = 1 : 3.227
Unit Cell V:
512.14 ų (Calculated from Unit Cell)
Twinning:
By reflection on (0001)?
Comment:
New polytype (Malcherek & Schlüter, 2016): trigonal, P-3m1, a = 5.6788(3), c = 18.3368(14) Å, V = 512.11 Å3, Z = 2.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 26 : Hadean detrital minerals | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 5: Initiation of plate tectonics | <3.5-2.5 |
| 40 : Regional metamorphism (greenschist, amphibolite, granulite facies) |
Type Occurrence of Magnesiotaaffeite-2N’2S
Synonyms of Magnesiotaaffeite-2N’2S
Other Language Names for Magnesiotaaffeite-2N’2S
Dutch:Magnesiotaaffeiet-2N’2S
Russian:Магнезиотаафеит-2N'2S
Simplified Chinese:塔菲石
Spanish:Bemagalita
Taaffeita
Taprobanita
Taaffeita
Taprobanita
Relationship of Magnesiotaaffeite-2N’2S to other Species
Member of:
Other Members of Magnesiotaaffeite subgroup:
| 'Magnesiotaaffeite-2N’2S2' | Mg3BeAl8O16 | Trig. 3m(32/m) : P3m1 |
| Magnesiotaaffeite-6N’3S | Mg2BeAl6O12 | Trig. 3m(32/m) : R3m |
Common Associates
Associations Based on Photo Data:
| 1 photo of Magnesiotaaffeite-2N’2S associated with Swedenborgite | NaBe4Sb5+O7 |
Related Minerals - Strunz-mindat Grouping
| 4.FC.05 | Dzhalindite | In(OH)3 |
| 4.FC.05 | Bernalite | Fe(OH)3 · nH2O (n = 0.0 to 0.25) |
| 4.FC.05 | Söhngeite | Ga(OH)3 |
| 4.FC.10 | Mushistonite | (Cu,Zn,Fe2+)[Sn(OH)6] |
| 4.FC.10 | Natanite | Fe2+[Sn(OH)6] |
| 4.FC.10 | Burtite | Ca[Sn(OH)6] |
| 4.FC.10 | Vismirnovite | Zn[Sn(OH)6] |
| 4.FC.10 | Wickmanite | Mn2+[Sn(OH)6] |
| 4.FC.10 | Schoenfliesite | Mg[Sn(OH)6] |
| 4.FC.15 | Jeanbandyite | Fe3+Sn(OH)5O |
| 4.FC.15 | Tetrawickmanite | Mn2+[Sn4+(OH)6] |
| 4.FC.15 | Nancyrossite | FeGeO6H5 |
| 4.FC.15 | Zincostottite | ZnGe(OH)6 |
| 4.FC.15 | Stottite | Fe2+[Ge4+(OH)6] |
| 4.FC.15 | Mopungite | Na[Sb5+(OH)6] |
| 4.FC.20 | Ferronigerite-2N1S | (Al,Fe,Zn)2(Al,Sn)6O11(OH) |
| 4.FC.20 | Magnesionigerite-6N6S | (Mg,Al,Zn)3(Al,Sn,Fe)8O15(OH) |
| 4.FC.20 | Magnesionigerite-2N1S | (Mg,Al,Zn)2(Al,Sn)6O11(OH) |
| 4.FC.20 | Ferronigerite-6N6S | (Al,Fe,Zn)3(Al,Sn,Fe)8O15(OH) |
| 4.FC.20 | Zinconigerite-2N1S | (Zn,Al,Mg)2(Al,Sn)6O11(OH) |
| 4.FC.20 | Zinconigerite-6N6S | Zn3Sn2Al16O30(OH)2 |
| 4.FC.25 | Magnesiotaaffeite-6N’3S | Mg2BeAl6O12 |
| 4.FC.25 | Ferrotaaffeite-2N’2S | Be(Fe,Mg,Zn)3Al8O16 |
Fluorescence of Magnesiotaaffeite-2N’2S
Sometimes fluoresces weak red 365nm LW UV, pale yellow to white in 254nm SW UV
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 Magnesiotaaffeite-2N’2S
mindat.org URL:
https://www.mindat.org/min-3863.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Magnesiotaaffeite-2N’2S
Reference List:
Anderson, B. W., Payne, C. J., Claringbull, G. F. (1951) Taaffeite, a new beryllium mineral, found as a cut gemstone. Mineralogical Magazine and Journal of the Mineralogical Society, 29 (215) 765-772 doi:10.1180/minmag.1951.029.215.03
Schmetzer, K. (1983) Crystal chemistry of natural Be-Mg-Al-oxides: taaffeite, taprobanite, musgravite. Neues Jahrbuch für Mineralogie - Abhandlungen, 146 (1). 15-28 doi:10.1127/njma/146/1983/15
Schmetzer, Karl (1983) Taaffeite or Taprobanite—A Problem of Mineralogical Nomenclature. The Journal of Gemmology, 18 (7) 623-634 doi:10.15506/jog.1983.18.7.623
Guinier, A., Bokij, G. B., Boll-Dornberger, K., Cowley, J. M., Ďurovič, S., Jagodzinski, H., Krishna, P., de Wolff, P. M., Zvyagin, B. B., Cox, D. E., et al. (1984) Nomenclature of polytype structures. Report of the International Union of Crystallography Ad hoc Committee on the Nomenclature of Disordered, Modulated and Polytype Structures. Acta Crystallographica Section A Foundations of Crystallography, 40 (4). 399-404 doi:10.1107/s0108767384000842
Schmetzer, Karl, Kiefert, Lore, Bernhardt, Heinz-Jürgen (2000) Purple to Purplish Red Chromium-Bearing Taaffeites. Gems & Gemology, 36 (1) 50-58 doi:10.5741/gems.36.1.50
Armbruster, Thomas (2002) Revised nomenclature of högbomite, nigerite, and taaffeite minerals. European Journal of Mineralogy, 14 (2) 389-395 doi:10.1127/0935-1221/2002/0014-0389
Schmetzer, Karl, Kiefert, Lore, Bernhardt, Heinz-Jürgen, Burford, Murray, Gunasekara, Dunil Palitha (2005) Iron- and zinc-rich gem-quality taaffeites from Sri Lanka. The Journal of Gemmology, 29 (5) 290-298 doi:10.15506/jog.2005.29.5.290
Localities for Magnesiotaaffeite-2N’2S
Showing 22 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.
Australia | |
| Teale (1980) |
Austria | |
| Bernhard (2008) |
China | |
| Fleischer (1959) +3 other references |
| Yuzhou Li (1990) | |
| Shimou Chen et al. (1981) +3 other references |
| Chen Jingzhong et al. (1989) +1 other reference |
Madagascar | |
| Ranorosoa (1986) | |
| Ranorosoa (1986) |
Myanmar | |
| Harald Schillhammer collection |
| Rolf Luetcke | |
| Themelis (2008) |
| Pavel M. Kartashov analytical data +1 other reference |
Russia | |
| Schmetzer (1983) |
Sri Lanka | |
| Fernando et al. (2005, September) |
| - (n.d.) |
| www.multicolour.com (2006) |
| Anderson et al. (1951) +1 other reference |
Sweden | |
| Gatedal (n.d.) +1 other reference |
Tanzania | |
| Schmetzer et al. (2007) +1 other reference |
Ukraine | |
| Kurylo et al. (2024) |
USA | |
| Dietrich (1990) |
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Xianghualing Mine, Xianghualing Sn-polymetallic ore field, Linwu Co., Chenzhou, Hunan, China