Log In
Ellenbergerite-(PO4)
This page is currently not sponsored. Click here to sponsor this page.
Formula:
(Mg,âŧ)2(Mg,Al)12(SiO3OH)6(PO3OH)(OH)6
Colour:
cream-red, greenish-blue
Crystal System:
Hexagonal
Said to be different from phosphate-poor ellenbergerite and phosphoellenbergerite. It is supposed to have a separate site occupied by phosphorus. It is also optically distinct from the above species. Its structure is said to be solved.
Found as (1) cream-red grains with magnesiostaurolite, pyrope, quartz, rutile, and talc, and (2) greenish-blue crystals in association with "magnesioaluminoceladonite", magnesiostaurolite, pyrope, and talc.
Not given in the Valid Unnamed Minerals list of IMA; not approved by IMA.
Found as (1) cream-red grains with magnesiostaurolite, pyrope, quartz, rutile, and talc, and (2) greenish-blue crystals in association with "magnesioaluminoceladonite", magnesiostaurolite, pyrope, and talc.
Not given in the Valid Unnamed Minerals list of IMA; not approved by IMA.
Unique Identifiers
Mindat ID:
47753
Long-form identifier:
mindat:1:1:47753:6
Similar Names
| Ellenbergerite | A valid IMA mineral species | Mg6(Mg,Ti,Zr,◻)2(Al,Mg)6Si8O28(OH)10 |
IMA Classification of Ellenbergerite-(PO4)
IMA status notes:
Published without approval
Physical Properties of Ellenbergerite-(PO4)
Colour:
Cream-red, greenish-blue
Optical Data of Ellenbergerite-(PO4)
Type:
Uniaxial (+)
RI values:
nω = 1.640(2) nε = 1.644(2)
Max. Birefringence:
δ = 0.004
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 Âĩm 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 Âĩm 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 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.
Comments:
data for the cream-red grains
Chemistry of Ellenbergerite-(PO4)
Mindat Formula:
(Mg,âŧ)2(Mg,Al)12(SiO3OH)6(PO3OH)(OH)6
Element Weights:
Crystallography of Ellenbergerite-(PO4)
Crystal System:
Hexagonal
Class (H-M):
6mm - Dihexagonal Pyramidal
Space Group:
P63mc
Setting:
P63mc
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.24 Ã | (60) |
| 4.52 Ã | (60) |
| 3.63 Ã | (90) |
| 3.157 Ã | (100) |
| 2.699 Ã | (70) |
| 2.369 Ã | (60) |
| 2.306 Ã | (60) |
| 2.212 Ã | (80) |
| 1.801 Ã | (60) |
| 1.552 Ã | (70) |
Comments:
data for the cream-red grains
Other Information
IR Spectrum:
data for the greenish-blue crystals in brackets, [cm-1]: 3575w (3570w), 3470 (3420), 3300sh, 1415w (1420), 1195 (1190sh), 1135, 1050 (1040s), 950sh, 925s (917), 800, (768), 700w, 630sh, 586 (590), 505sh (510sh), (467s), 472s, 400
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 Ellenbergerite-(PO4)
mindat.org URL:
https://www.mindat.org/min-47753.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
Mineral Dealers:
References for Ellenbergerite-(PO4)
Localities for Ellenbergerite-(PO4)
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
â - 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.
Italy | |
| Chukanov (2014) |
