Reinhardbraunsite
A valid IMA mineral species
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About Reinhardbraunsite
Reinhard Brauns
Formula:
Ca5(SiO4)2(OH,F)2
Colour:
Pale pink
Lustre:
Vitreous
Hardness:
5 - 6
Specific Gravity:
2.85
Crystal System:
Monoclinic
Member of:
Name:
Named in honor of Dr. Reinhard Brauns (20 August 20, 1867, Eiterfeld, near Cassel, Germany - 28 January 1937), Professor of Mineralogy and Petrography at the University of Bonn. He had over 200 publications on different aspects of mineralogy and petrography including studies on the optical anomalies of crystals, a treatise on chemical mineralogy, the properties of gem minerals, and many articles dealing with the rocks and minerals of the volcanic areas of the Rheinland and the famous Laacher See district.
Isostructural with:
Reinhardbraunsite is a mineral in the humite Group. It is the (OH)-dominant member in a series with Kumtyubeite. The Reinhardbraunite-Kumtyubeite series form the Ca-dominant equivalent of the chondrodite-hydroxylchondrodite series. A mineral with a reinhardbraunsite composition was synthesized in 1958 and named calciochondrodite, but the naturally occurring mineral was given the name reinhardbraunsite upon its discovery in 1983.
Reinhardbraunsite is, like all Ca-humites, a product of high-temperature and low-pressure environments, and it is a product of contact metamorphism between high-temperature magma/lava flows and carbonate rocks.
Reinhardbraunsite is, like all Ca-humites, a product of high-temperature and low-pressure environments, and it is a product of contact metamorphism between high-temperature magma/lava flows and carbonate rocks.
Unique Identifiers
Mindat ID:
3387
Long-form identifier:
mindat:1:1:3387:5
IMA Classification of Reinhardbraunsite
Approved
IMA Formula:
Ca5(SiO4)2(OH)2
Approval year:
1980
First published:
1983
Classification of Reinhardbraunsite
9.AF.45
9 : SILICATES (Germanates)
A : Nesosilicates
F : Nesosilicates with additional anions; cations in [4], [5] and/or only [6] coordination
9 : SILICATES (Germanates)
A : Nesosilicates
F : Nesosilicates with additional anions; cations in [4], [5] and/or only [6] coordination
52.3.2b.3
52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
3 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] coordination only
52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
3 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] coordination only
14.2.7
14 : Silicates not Containing Aluminum
2 : Silicates of Cu
14 : Silicates not Containing Aluminum
2 : Silicates of Cu
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 |
|---|---|---|
| Rbn | 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 Reinhardbraunsite
Vitreous
Transparency:
Translucent
Colour:
Pale pink
Streak:
White
Hardness:
5 - 6 on Mohs scale
Cleavage:
Distinct/Good
On {001}
On {001}
Fracture:
Conchoidal
Density:
2.85(2) g/cm3 (Measured) 2.885 g/cm3 (Calculated)
Optical Data of Reinhardbraunsite
Type:
Biaxial (-)
RI values:
nα = 1.606(2) nβ = 1.617(2) nγ = 1.620(2)
2V:
Measured: 44° to 50°, Calculated: 54°
Max. Birefringence:
δ = 0.014
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:
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.
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.
Dispersion:
r > v, distinct
Optical Extinction:
Z = b; X ∧ c = 18(1)°.
Chemistry of Reinhardbraunsite
Mindat Formula:
Ca5(SiO4)2(OH,F)2
Element Weights:
Common Impurities:
H2O,P
Crystallography of Reinhardbraunsite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 11.45 Å, b = 5.05 Å, c = 8.84 Å
β = 108.91°
β = 108.91°
Ratio:
a:b:c = 2.267 : 1 : 1.75
Unit Cell V:
483.56 ų (Calculated from Unit Cell)
Z:
2
Twinning:
Single and multiple twinning on {001}, noted only in minute recrystallized grains.
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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CIF File Best | x | y | z | a | b | c
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0015696 | Reinhardbraunsite | Kirfel A, Hamm H M, Will G (1983) The crystal structure of reinhardbraunsite, Ca5(SiO4)2(OH,F)2, a new mineral of the calcio-chondrodite type Tschermaks Mineralogische und Petrographische Mitteilungen 31 137-150 | 1983 | synthetic | 0 | 293 | |
| 0015581 | Reinhardbraunsite | Kuznetsova T P, Nevskii N N, Ilyukhin V V, Belov N V (1980) Refinement of the crystal structure of calcium chondrodite Ca5[SiO4]2(OH)2=Ca(OH)2*2Ca2SiO4 Soviet Physics Crystallography 25 91-92 | 1980 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 1.902 Å | (100) |
| 3.035 Å | (80) |
| 2.903 Å | (75) |
| 3.322 Å | (50) |
| 2.941 Å | (50) |
| 1.894 Å | (50) |
| 1.658 Å | (45) |
Comments:
Bellerberg volcano, Germany. Data from the type description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 9 : Lava/xenolith minerals (hornfels, sanidinite facies) | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 51 : Pyrometamorphic minerals (see also #54 and #56) | <0.36 |
Type Occurrence of Reinhardbraunsite
General Appearance of Type Material:
Anhedral to subhedral grains, up to 3 mm.
Place of Conservation of Type Material:
Mineralogical-Petrological Institute, University of Bonn, Bonn, Germany.
Geological Setting of Type Material:
Occurs in xenoliths in scoria.
Associated Minerals at Type Locality:
Synonyms of Reinhardbraunsite
Other Language Names for Reinhardbraunsite
Relationship of Reinhardbraunsite to other Species
Member of:
Other Members of Chegemite Subgroup:
| Chegemite | Ca7(SiO4)3(OH)2 | Orth. mmm(2/m2/m2/m) |
| Edgrewite | Ca9(SiO4)4F2 | Mon. 2/m : P21/b |
| Fluorchegemite | Ca7(SiO4)3F2 | Orth. mmm(2/m2/m2/m) |
| Hydroxyledgrewite | Ca9(SiO4)4(OH)2 | Mon. 2/m : P21/b |
| Kumtyubeite | Ca5(SiO4)2F2 | Mon. 2/m : P21/b |
Common Associates
Associations Based on Photo Data:
| 2 photos of Reinhardbraunsite associated with 'Ellestadite' | |
| 1 photo of Reinhardbraunsite associated with Brownmillerite | Ca2Fe3+AlO5 |
Related Minerals - Strunz-mindat Grouping
| 9.AF. | Chegemite | Ca7(SiO4)3(OH)2 |
| 9.AF. | Jingwenite-(Y) | YAlV4+(SiO4)O2(OH)2 |
| 9.AF. | Barwoodite | Mn2+6Nb5+(SiO4)2O3(OH)3 |
| 9.AF.05 | Sillimanite | Al2(SiO4)O |
| 9.AF.05 | 'Xenolite' | Al10Si8O31 |
| 9.AF.10 | Kanonaite | Mn3+Al(SiO4)O |
| 9.AF.10 | Andalusite | Al2(SiO4)O |
| 9.AF.15 | Kyanite | Al2(SiO4)O |
| 9.AF.20 | Krieselite | Al2(GeO4)F2 |
| 9.AF.20 | Mullite | Al4+2xSi2-2xO10-x |
| 9.AF.23 | Boromullite | Al9BSi2O19 |
| 9.AF.25 | Yoderite | Mg(Al,Fe3+)3(SiO4)2O(OH) |
| 9.AF.30 | Zincostaurolite | Zn2Al9Si4O23(OH) |
| 9.AF.30 | Staurolite | Fe2+2Al9Si4O23(OH) |
| 9.AF.30 | Magnesiostaurolite | Mg(Mg,Li)3(Al,Mg)18Si8O44(OH)4 |
| 9.AF.35 | Topaz | Al2(SiO4)(F,OH)2 |
| 9.AF.40 | Norbergite | Mg3(SiO4)F2 |
| 9.AF.45 | Chondrodite | Mg5(SiO4)2F2 |
| 9.AF.45 | Kumtyubeite | Ca5(SiO4)2F2 |
| 9.AF.45 | Hydroxylchondrodite | Mg5(SiO4)2(OH)2 |
| 9.AF.45 | Alleghanyite | Mn2+5(SiO4)2(OH)2 |
| 9.AF.50 | 'Unnamed (Ca-analogue of Humite)' | Ca7(SiO4)4F2 |
| 9.AF.50 | Humite | Mg7(SiO4)3F2 |
| 9.AF.50 | Manganhumite | Mn2+7(SiO4)3(OH)2 |
| 9.AF.50 | 'Unnamed (OH-analogue of humite)' | Mg7(SiO4)3(OH)2 |
| 9.AF.50 | Fluorchegemite | Ca7(SiO4)3F2 |
| 9.AF.55 | Hydroxylclinohumite | Mg9(SiO4)4(OH)2 |
| 9.AF.55 | Clinohumite | Mg9(SiO4)4F2 |
| 9.AF.55 | Sonolite | Mn2+9(SiO4)4(OH)2 |
| 9.AF.60 | Leucophoenicite | Mn2+7(SiO4)3(OH)2 |
| 9.AF.65 | Ribbeite | Mn2+5(SiO4)2(OH)2 |
| 9.AF.70 | Jerrygibbsite | Mn2+9(SiO4)4(OH)2 |
| 9.AF.75 | Franciscanite | Mn2+6(V5+,◻)2(SiO4)2(O,OH)6 |
| 9.AF.75 | Scorticoite | Mn6(Sb,◻)Σ2(SiO4)2O3(OH)3 |
| 9.AF.75 | Welinite | Mn2+6(W6+,Mg)2(SiO4)2(O,OH)6 |
| 9.AF.75 | Örebroite | Mn2+3(Sb5+,Fe3+)(SiO4)(O,OH)3 |
| 9.AF.80 | Ellenbergerite | Mg6(Mg,Ti,Zr,◻)2(Al,Mg)6Si8O28(OH)10 |
| 9.AF.85 | Magnesiochloritoid | MgAl2O(SiO4)(OH)2 |
| 9.AF.85 | Ottrélite | Mn2+Al2O(SiO4)(OH)2 |
| 9.AF.85 | Chloritoid | Fe2+Al2O(SiO4)(OH)2 |
| 9.AF.90 | Olmiite | CaMn2+[SiO3(OH)](OH) |
| 9.AF.90 | Poldervaartite | CaCa[SiO3(OH)](OH) |
| 9.AF.95 | Pilawite-(Y) | Ca2Y2Al4(SiO4)4O2(OH)2 |
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 Reinhardbraunsite
mindat.org URL:
https://www.mindat.org/min-3387.html
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References for Reinhardbraunsite
Reference List:
Dunn, P.J.; Grice, J.D.; Fleischer, M.; Pabst, A. (1983) New mineral names. American Mineralogist, 68 (9-10). 1038-1041
Kirfel, A., Hamm, H. -M., Will, G. (1983) The crystal structure of reinhardbraunsite, Ca5(SiO4)2(OH,F)2, a new mineral of the calcio-chondrodite type. TMPM Tschermaks Mineralogische und Petrographische Mitteilungen, 31 (1). 137-150 doi:10.1007/bf01084766
Galuskina, I. O., Lazic, B., Armbruster, T., Galuskin, E. V., Gazeev, V. M., Zadov, A. E., Pertsev, N. N., Jezak, L., Wrzalik, R., Gurbanov, A. G. (2009) Kumtyubeite Ca5(SiO4)2F2 — A new calcium mineral of the humite group from Northern Caucasus, Kabardino-Balkaria, Russia. American Mineralogist, 94 (10) 1361-1370 doi:10.2138/am.2009.3256
Localities for Reinhardbraunsite
Showing 13 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.
Czech Republic | |
| Hršelová et al. (2013) |
Germany | |
| Blaß et al. (2015) |
| Hamm et al. (1983) |
| Juroszek et al. (2024) | |
| Galuskin et al. (2016) | |
| Schüller et al. (1986) |
Middle East | |
| Vapnik et al. (2006) | |
Romania | |
| Szakáll |
| Szakáll et al. (2010) | |
Russia | |
| Bailau +2 other references |
| Galuskin et al. (2011) |
| Galuskin +9 other references | |
Uganda | |
| Barker et al. (1989) |
Quick NavTopAbout ReinhardbraunsiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Caspar quarry, Ettringen, Vordereifel, Mayen-Koblenz, Rhineland-Palatinate, Germany