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Moraesite
A valid IMA mineral species - grandfathered
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About Moraesite
Luciano Jacques de Moraes (1896–1968)
Formula:
Be2(PO4)(OH) · 4H2O
Colour:
White
Lustre:
Silky
Specific Gravity:
1.805
Crystal System:
Monoclinic
Name:
Named in 1953 by Marie Louise Lindberg (Smith), William T. Pecora, and Aluízio Licínio de Miranda Barbosa in honor of Dr. Luciano Jacques de Moraes [1896–1968], Brazilian mineralogist and geologist.
This page provides mineralogical data about Moraesite.
Unique Identifiers
Mindat ID:
2778
Long-form identifier:
mindat:1:1:2778:2
Similar Names
| Marosite (of Cook and Sherwood) | A rock subtype |
| Marosite (of Iddings) | A rock subtype |
IMA Classification of Moraesite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Be2PO4(OH)·4H2O
First published:
1953
Classification of Moraesite
8.DA.05
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
A : With small (and occasionally larger) cations
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
A : With small (and occasionally larger) cations
42.6.1.1
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
6 : A2(XO4)Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
6 : A2(XO4)Zq·xH2O
19.3.1
19 : Phosphates
3 : Phosphates of Be and Mg
19 : Phosphates
3 : Phosphates of Be and Mg
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 |
|---|---|---|
| Mae | 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 Moraesite
Silky
Transparency:
Translucent
Colour:
White
Streak:
White
Cleavage:
Perfect
Parallel to b and c axes.
Parallel to b and c axes.
Density:
1.805 g/cm3 (Measured) 1.806 g/cm3 (Calculated)
Comment:
Measured with a pycnometer
Optical Data of Moraesite
Type:
Biaxial (-)
RI values:
nα = 1.462 nβ = 1.482 nγ = 1.490
2V:
Measured: 65° , Calculated: 62°
Max. Birefringence:
δ = 0.028
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:
Moderate (negative)
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 strong
Optical Extinction:
Z = b, Y ∧ c = 11°.
Chemistry of Moraesite
Mindat Formula:
Be2(PO4)(OH) · 4H2O
Element Weights:
Elements listed:
Crystallography of Moraesite
Crystal System:
Monoclinic
Class (H-M):
m - Domatic
Space Group:
Bb
Setting:
Cc
Cell Parameters:
a = 8.553(6) Å, b = 36.957(18) Å, c = 7.155(8) Å
β = 97.93°
β = 97.93°
Ratio:
a:b:c = 0.231 : 1 : 0.194
Unit Cell V:
2,240.02 ų (Calculated from Unit Cell)
Z:
12
Morphology:
Acicular parallel to the c-axis [001], and tabular parallel to the orthopinacoid {100}. The pyramid face (131) is usually better developed than (131) and in some crystals gives the general appearance of a basal plane of a triclinic mineral. The faces (130) and (130) are better developed than (130) and (130). The orthopinacoid and prism faces of the forms {100} and {130} are striated parallel to the c-axis.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Display Options
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2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
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Rotation
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Labels
Console Off | On | Grey | Yellow
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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) |
|---|---|---|---|---|---|---|---|
| 0011025 | Moraesite | Merlino S, Pasero M (1992) Crystal chemistry of beryllophosphates: The crystal structure of moraesite, Be2(PO4)(OH)*4H2O Zeitschrift fur Kristallographie 201 253-262 |  | 1992 | Humaita, Brazil | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.00 Å | (100) |
| 3.278 Å | (90) |
| 4.24 Å | (60) |
| 3.023 Å | (60) |
| 2.819 Å | (60) |
| 6.15 Å | (40) |
| 2.325 Å | (40) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) |
Type Occurrence of Moraesite
General Appearance of Type Material:
Occurs in tufted or radial aggregates, in fibrous coatings, or in spherulitic masses Delicate needles grade into crusts with a coarse fibrous structure. Crystals are minute singly terminated needle-like laths.
Place of Conservation of Type Material:
National Museum, Rio de Janeiro, Brazil.
National School of Mines, Paris, France, number 50740.
National Museum of Natural History (Smithsonian), Washington, D.C., USA, number 106577.
National School of Mines, Paris, France, number 50740.
National Museum of Natural History (Smithsonian), Washington, D.C., USA, number 106577.
Geological Setting of Type Material:
Pegmatite
Associated Minerals at Type Locality:
Other Language Names for Moraesite
Common Associates
Associations Based on Photo Data:
| 13 photos of Moraesite associated with Beryllonite | NaBePO4 |
| 12 photos of Moraesite associated with Hydroxylherderite | CaBe(PO4)(OH) |
| 9 photos of Moraesite associated with Zanazziite | Ca2Mg5Be4(PO4)6(OH)4 · 6H2O |
| 8 photos of Moraesite associated with Quartz | SiO2 |
| 8 photos of Moraesite associated with Eosphorite | Mn2+Al(PO4)(OH)2 · H2O |
| 6 photos of Moraesite associated with Greifensteinite | Ca2Fe2+5Be4(PO4)6(OH)4 · 6H2O |
| 6 photos of Moraesite associated with Roscherite | Ca2Mn2+5Be4(PO4)6(OH)4 · 6H2O |
| 5 photos of Moraesite associated with Beryl | Be3Al2(Si6O18) |
| 4 photos of Moraesite associated with Wilancookite | (Ba5Li2◻)Ba6Be24P24O96 · 26H2O |
| 4 photos of Moraesite associated with Albite | Na(AlSi3O8) |
Related Minerals - Strunz-mindat Grouping
| 8.DA.05 | Bearsite | Be2(AsO4)(OH) · 4H2O |
| 8.DA.10 | Zanazziite | Ca2Mg5Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Atencioite | Ca2Fe2+3Mg2Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Guimarãesite | Ca2Be4Zn5(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Footemineite | Ca2Mn2+Mn2+2Mn2+2Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Greifensteinite | Ca2Fe2+5Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Roscherite | Ca2Mn2+5Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Ruifrancoite | Ca2(◻,Mn)2(Fe3+,Mn,Mg)4Be4(PO4)6(OH)4(OH,H2O)2 · 4H2O |
| 8.DA.10 | Okruschite | Ca2Mn2+5Be4(AsO4)6(OH)4 · 6H2O |
| 8.DA.15 | Uralolite | Ca2Be4(PO4)3(OH)3 · 5H2O |
| 8.DA.20 | Weinebeneite | CaBe3(PO4)2(OH)2 · 4H2O |
| 8.DA.25 | Tiptopite | K2(Na,Ca)2Li3Be6(PO4)6(OH)2 · H2O |
| 8.DA.40 | Spencerite | Zn4(PO4)2(OH)2 · 3H2O |
| 8.DA.45 | Glucine | CaBe4(PO4)2(OH)4 · 0.5H2O |
Other Information
Notes:
Soluble in dilute HCl, HNO3, and H2SO4.
When heated, it decrepitates, giving off water, but does not fuse into a globular mass.
When heated, it decrepitates, giving off water, but does not fuse into a globular mass.
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 Moraesite
mindat.org URL:
https://www.mindat.org/min-2778.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Moraesite
Reference List:
Lindberg, M. L., Pecora, W. T., Barbosa, and A. L. deM. (1953) Moraesite, a new hydrous beryllium phosphate from Minas Gerais, Brazil. American Mineralogist, 38 (11-12) 1126-1133
Localities for Moraesite
Showing 43 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.
Quick NavTopAbout MoraesiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Linópolis, Divino das Laranjeiras, Minas Gerais, Brazil