Mengxianminite
A valid IMA mineral species
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About Mengxianminite
Meng Xianmin
Formula:
(Ca,Na)2Sn2(Mg,Fe)3Al8[(BO3)(BeO4)O6]2
Colour:
Green
Lustre:
Vitreous
Hardness:
8
Specific Gravity:
4.170 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honor of Meng Xianmin (孟宪民) (2 February 1900, Wujin County, Jiangsu Province, China – 18 February 1969, Beijing, China), a famous geologist in China, who "devoted himself to work on mineral identification and theory of mineralization in deposits of non-ferrous metals and made significant contributions to the research of ore deposits in China."
New structure type. Unique combination of elements. Mengxianminite is the first borate mineral with both Sn and Be, likely crystallized under F-rich conditions at late stages of the Xianghualing skarn. Other Sn-B minerals are nordenskiöldine, tusionite and vistepite. Third Sn-Be mineral after sverigeite and sørensenite.
Unique Identifiers
Mindat ID:
47016
Long-form identifier:
mindat:1:1:47016:2
Similar Names
| Mengxianminite (of Huang et al.) | Valid as an unnamed mineral | (Ca,Na)3(Fe,Mn)2Mg2(Sn,Zn)5Al8O29 |
IMA Classification of Mengxianminite
Approved
IMA Formula:
Ca2Sn4+2Mg3Al8[(BO3)(BeO4)O6]2
Approval year:
2015
First published:
2017
Type description reference:
Can, Rao, Hatert, Frédéric, Dal Bo, Fabrice, Wang, Rucheng, Gu, Xiangping, Baijot, Maxime (2017) Mengxianminite (Ca2Sn2Mg3Al8[(BO3)(BeO4)O6]2) a new borate mineral from Xianghualing skarn, Hunan Province, China, with a highly unusual chemical combination (B + Be + Sn) American Mineralogist, 102 (10) 2136-2141 doi:10.2138/am-2017-5919
Classification of Mengxianminite
6.AB.90
6 : BORATES
A : Monoborates
B : BO3, with additional anions; 1(D) + OH, etc.
6 : BORATES
A : Monoborates
B : BO3, with additional anions; 1(D) + OH, etc.
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Mgx | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Mengxianminite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Green
Hardness:
8 on Mohs scale
Hardness Data:
Estimated
Tenacity:
Brittle
Cleavage:
Perfect
Perfect cleavage on {100} and good cleavage on {010}
Perfect cleavage on {100} and good cleavage on {010}
Fracture:
Irregular/Uneven
Density:
4.170 g/cm3 (Calculated)
Optical Data of Mengxianminite
Type:
Biaxial (-)
RI values:
nα = 1.80(2) nβ = 1.83(2) nγ = 1.84(2)
Max. Birefringence:
δ = 0.040
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 biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
No measured or calculated 2V is on file for this mineral, so the value used here (59°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
No measured or calculated 2V is on file for this mineral, so the value used here (59°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Optical Extinction:
X = a; Y = b; Z = c.
Chemistry of Mengxianminite
Mindat Formula:
(Ca,Na)2Sn2(Mg,Fe)3Al8[(BO3)(BeO4)O6]2
Element Weights:
Crystallography of Mengxianminite
Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Space Group:
Fdd2
Cell Parameters:
a = 60.699(4) Å, b = 9.914(1) Å, c = 5.745(1) Å
Ratio:
a:b:c = 6.123 : 1 : 0.579
Unit Cell V:
3457.4 ų
Z:
8
Morphology:
Subhedral to euhedral green crystals from 20 to 200 μm long.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.00 Å | (35) |
| 2.931 Å | (100) |
| 2.475 Å | (29) |
| 2.430 Å | (30) |
| 2.375 Å | (100) |
| 2.028 Å | (52) |
| 1.807 Å | (35) |
| 1.530 Å | (98) |
Reference:
Can, Rao, Hatert, Frédéric, Dal Bo, Fabrice, Wang, Rucheng, Gu, Xiangping, Baijot, Maxime (2017) Mengxianminite (Ca2Sn2Mg3Al8[(BO3)(BeO4)O6]2) a new borate mineral from Xianghualing skarn, Hunan Province, China, with a highly unusual chemical combination (B + Be + Sn) American Mineralogist, 102 (10) 2136-2141 doi:10.2138/am-2017-5919
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) |
Type Occurrence of Mengxianminite
General Appearance of Type Material:
Subhedral to euhedral green crystals from 20 to 200 μm long in a hsianghualite vein.
Place of Conservation of Type Material:
Cotype material: (1) Geological Museum of China, No. 16, Yangrou Hutong, Xisi, Beijing 100031, P.R. of China, catalogue number M13293; (2) Laboratory of Mineralogy, University of Liège, Belgium, catalogue number 20395.
Empirical Formula of Type Material:
(Ca1.64,Na0.39)Σ2.03(Sn1.85,Zn0.24)Σ2.09(Mg1.75, Fe0.72,Al0.42,Mn0.19,Ti0.01)Σ3.09Al8[(B1.01O3)(Be0.94O4)O6]2
Chemical Analysis of Type Material:
| Al2O3 | 40.00 % |
|---|---|
| SnO2 | 25.96 % |
| MgO | 6.57 % |
| CaO | 8.56 % |
| FeO | 4.83 % |
| B2O3 | 6.53 % |
| BeO | 4.37 % |
| ZnO | 1.81 % |
| MnO | 1.23 % |
| Na2O | 1.13 % |
| TiO2 | 0.10 % |
| SiO2 | 0.04 % |
| Total: | 101.13 % |
Geological Setting of Type Material:
Xianghualing skarn, Linwu County, Hunan Province, China.
Associated Minerals at Type Locality:
Reference:
Can, Rao, Hatert, Frédéric, Dal Bo, Fabrice, Wang, Rucheng, Gu, Xiangping, Baijot, Maxime (2017) Mengxianminite (Ca2Sn2Mg3Al8[(BO3)(BeO4)O6]2) a new borate mineral from Xianghualing skarn, Hunan Province, China, with a highly unusual chemical combination (B + Be + Sn) American Mineralogist, 102 (10) 2136-2141 doi:10.2138/am-2017-5919
Synonyms of Mengxianminite
Other Language Names for Mengxianminite
Dutch:Mengxianminiet
German:Mengxianminit
Related Minerals - Strunz-mindat Grouping
| 6.AB. | Chubarovite | KZn2(BO3)Cl2 |
| 6.AB. | Rhabdoborite-(Mo) | Mg12Mo6+1.33O6(BO3)6F2 |
| 6.AB.05 | Hambergite | Be2(BO3)(OH) |
| 6.AB.10 | Berborite | Be2(BO3)(OH) · H2O |
| 6.AB.15 | Jeremejevite | Al6(BO3)5(F,OH)3 |
| 6.AB.20 | Yuanfuliite | Mg(Fe3+,Al)O(BO3) |
| 6.AB.20 | Warwickite | (Mg,Ti,Fe,Al)2O(BO3) |
| 6.AB.25 | Karlite | (Mg,Al)6.5(BO3)3(OH)4(◻,Cl)0.5 |
| 6.AB.30 | Marinaite | Cu2Fe3+O2(BO3) |
| 6.AB.30 | Savelievaite | Mg2Cr3+O2(BO3) |
| 6.AB.30 | Fredrikssonite | Mg2Mn3+O2(BO3) |
| 6.AB.30 | Vonsenite | Fe2+2Fe3+(BO3)O2 |
| 6.AB.30 | Ludwigite | Mg2Fe3+(BO3)O2 |
| 6.AB.30 | Azoproite | (Mg,Fe2+)2(Fe3+,Ti,Mg)(BO3)O2 |
| 6.AB.30 | Bonaccordite | Ni2Fe3+(BO3)O2 |
| 6.AB.35 | Folvikite | Sb5+Mn3+(Mg,Mn2+)10O8(BO3)4 |
| 6.AB.35 | Pinakiolite | (Mg,Mn2+)2Mn3+(BO3)O2 |
| 6.AB.40 | Takéuchiite | (Mg,Mn2+)2(Mn3+,Fe3+)(BO3)O2 |
| 6.AB.40 | Blatterite | Sb5+3(Mn3+,Fe3+)9(Mn2+,Mg)35(BO3)16O32 |
| 6.AB.40 | Orthopinakiolite | (Mg,Mn2+)2Mn3+(BO3)O2 |
| 6.AB.40 | Chestermanite | Mg2(Fe3+,Mn3+,Al,Sb3+)(BO3)O2 |
| 6.AB.45 | Aluminomagnesiohulsite | (Mg,Fe2+)2(Al,Mg,Sn)(BO3)O2 |
| 6.AB.45 | Hulsite | Fe2+2Fe3+O2(BO3) |
| 6.AB.45 | Magnesiohulsite | Mg2Fe3+O2(BO3) |
| 6.AB.50 | Fluoborite | Mg3(BO3)(F,OH)3 |
| 6.AB.50 | Hydroxylborite | Mg3(BO3)(OH)3 |
| 6.AB.55 | Shabynite | Mg5(BO3)(OH)5(Cl,OH)2 · 4H2O |
| 6.AB.55 | Wightmanite | Mg5(BO3)O(OH)5 · 2H2O |
| 6.AB.60 | Gaudefroyite | Ca4Mn3+2-3(BO3)3(CO3)(O,OH)3 |
| 6.AB.65 | Sakhaite | Ca48Mg16(BO3)32(CO3)16 · 2(H2O,HCl) |
| 6.AB.70 | Harkerite | Ca48Mg16[AlSi4O15(OH)]4(BO3)16(CO3)16 · 2(H2O,HCl) |
| 6.AB.75 | Pertsevite-(F) | Mg2(BO3)(F,OH) |
| 6.AB.75 | Pertsevite-(OH) | Mg2(BO3)(OH) |
| 6.AB.80 | Jacquesdietrichite | Cu2(H2BO3)(OH)3 |
| 6.AB.85 | Rhabdoborite-(V) | Mg12(V5+,Mo6+,W6+)1.5O6{[BO3]6-x[(P,As)O4]xF2-x} (x < 1) |
| 6.AB.85 | Rhabdoborite-(W) | Mg12(W6+,V5+)1.5O6{[BO3]6-x[(P,As)O4]xF2-x} |
| 6.AB.85 | Painite | CaZrAl9(BO3)O15 |
Fluorescence of Mengxianminite
Do not fluoresce in long- or short-wave ultraviolet light.
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 Mengxianminite
mindat.org URL:
https://www.mindat.org/min-47016.html
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References for Mengxianminite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2016) New minerals and nomenclature modifications approved in 2015 and 2016, CNMNC Newsletter No 29. Mineralogical Magazine, 80 (1) 199-205 doi:10.1180/minmag.2016.080.080
Can, Rao, Hatert, Frédéric, Dal Bo, Fabrice, Wang, Rucheng, Gu, Xiangping, Baijot, Maxime (2017) Mengxianminite (Ca2Sn2Mg3Al8[(BO3)(BeO4)O6]2) a new borate mineral from Xianghualing skarn, Hunan Province, China, with a highly unusual chemical combination (B + Be + Sn) American Mineralogist, 102 (10) 2136-2141 doi:10.2138/am-2017-5919
Localities for Mengxianminite
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.
China (TL) | |
| Hålenius et al. (2016) +1 other reference |
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Xianghualing Sn-polymetallic ore field, Linwu Co., Chenzhou, Hunan, China