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Dittmarite
A valid IMA mineral species - grandfathered
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About Dittmarite
William Dittmar
Formula:
(NH4)Mg(PO4) · H2O
Colour:
Colourless
Hardness:
5
Specific Gravity:
2.15
Crystal System:
Orthorhombic
Name:
Named in 1887 (described in 1902) by R.W. Emerson MacIvor in honor of William Dittmar (14/15 April 1833, Umstadt, Germany – 9 February 1892, Glasgow, Scotland), Professor of Chemistry, University of Glasgow, Glasgow, Scotland.
Isostructural with:
This page provides mineralogical data about Dittmarite.
Unique Identifiers
Mindat ID:
1297
Long-form identifier:
mindat:1:1:1297:9
IMA Classification of Dittmarite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
(N3-H4)MgPO4·H2O
First published:
1887
Classification of Dittmarite
8.CH.20
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
H : With large and medium-sized cations, RO4:H2O < 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
H : With large and medium-sized cations, RO4:H2O < 1:1
40.1.2.1
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
1 : AB(XO4)·xH2O
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
1 : AB(XO4)·xH2O
19.3.22
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 |
|---|---|---|
| Dmr | 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 Dittmarite
Transparency:
Transparent
Colour:
Colourless
Streak:
White
Hardness:
5 on Mohs scale
Density:
2.15 g/cm3 (Measured) 2.19 g/cm3 (Calculated)
Optical Data of Dittmarite
Type:
Biaxial (-)
RI values:
nα = 1.549 nβ = 1.569 nγ = 1.571
2V:
Measured: 40° , Calculated: 34°
Max. Birefringence:
δ = 0.022
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:
Low (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:
none
Chemistry of Dittmarite
Mindat Formula:
(NH4)Mg(PO4) · H2O
Element Weights:
Crystallography of Dittmarite
Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Space Group:
Pmn21
Cell Parameters:
a = 5.606 Å, b = 8.758 Å, c = 4.788 Å
Ratio:
a:b:c = 0.64 : 1 : 0.547
Unit Cell V:
235.08 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Rhombic crystals.
Comment:
Cell parameters from Mrose 1971.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.77 Å | (100) |
| 2.80 Å | (50) |
| 2.92 Å | (40) |
| 4.72 Å | (30) |
| 4.20 Å | (25) |
| 2.50 Å | (20) |
| 2.28 Å | (10) |
Comments:
Skipton lava tube caves, Australia. ICDD 20-663.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 52 : Guano- and urine-derived minerals | <0.4 |
Type Occurrence of Dittmarite
General Appearance of Type Material:
Small rhombic, transparent crystals.
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
A dry bat guano cave.
Associated Minerals at Type Locality:
Other Language Names for Dittmarite
Related Minerals - Strunz-mindat Grouping
| 8.CH. | Georgeliuite | Ca2Mn3+3O2(AsO4)3(H2O)2 · H2O |
| 8.CH.05 | Natrowalentaite | [Fe3+0.5Na0.5(H2O)6][NaAs3+2(Fe3+2.33W6+0.67)(PO4)2O7] |
| 8.CH.05 | Walentaite | [Mn2+(H2O)6][◻As3+3Fe3+3(PO4)2O7] |
| 8.CH.05 | Halilsarpite | [Mg(H2O)6][CaAs3+2(Fe3+2.67Mo6+0.33)(AsO4)2O7] |
| 8.CH.10 | Anapaite | Ca2Fe2+(PO4)2 · 4H2O |
| 8.CH.15 | Picropharmacolite | Ca4Mg(AsO4)2(HAsO4)2 · 11H2O |
| 8.CH.20 | Niahite | (NH4)Mn2+(PO4) · H2O |
| 8.CH.25 | Taranakite | K3Al5(PO3OH)6(PO4)2 · 18H2O |
| 8.CH.25 | Francoanellite | K3Al5(PO3OH)6(PO4)2 · 12H2O |
| 8.CH.25 | Macivorite | (NH4)3Al5(PO3OH)6(PO4)2 · 18H2O |
| 8.CH.30 | Schertelite | (NH4)2MgH2(PO4)2 · 4H2O |
| 8.CH.35 | Hannayite | (NH4)2Mg3H4(PO4)4 · 8H2O |
| 8.CH.40 | Hazenite | KNaMg2(PO4)2 · 14H2O |
| 8.CH.40 | Struvite-(K) | KMg(PO4) · 6H2O |
| 8.CH.40 | Struvite | (NH4)Mg(PO4) · 6H2O |
| 8.CH.45 | Rimkorolgite | (Mg,Mn)5(Ba,Sr,Ca)(PO4)4 · 8H2O |
| 8.CH.50 | Bakhchisaraitsevite | Na2Mg5(PO4)4 · 7H2O |
| 8.CH.55 | Smolyaninovite | Co3Fe3+2(AsO4)4 · 11H2O |
| 8.CH.55 | Fahleite | CaZn5Fe3+2(AsO4)6 · 14H2O |
| 8.CH.60 | Barahonaite-(Fe) | (Ca,Cu,Na,Fe3+,Al)12Fe3+2(AsO4)8(OH,Cl)x · nH2O |
| 8.CH.60 | Barahonaite-(Al) | (Ca,Cu,Na,Fe3+,Al)12Al2(AsO4)8(OH,Cl)x · nH2O |
| 8.CH.70 | Epifanovite | NaCaCu5(PO4)4[AsO2(OH)2] · 7H2O |
| 8.CH.75 | Esdanaite-(Ce) | NaMnCe(PO4)2 · 4H2O |
Other Information
Thermal Behaviour:
Does not lose water when exposed to the atmosphere, but when heated to 100-105°C for a time, it gives up water and loses transparency.
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 Dittmarite
mindat.org URL:
https://www.mindat.org/min-1297.html
Please feel free to link to this page.
Please feel free to link to this page.
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Mineral Dealers:
References for Dittmarite
Reference List:
Šoptrajanov, Bojan, Stefov, Viktor, Kuzmanovski, Igor, Jovanovski, Gligor, Lutz, H.Dieter, Engelen, Bernward (2002) Very low H–O–H bending frequencies. IV. Fourier transform infrared spectra of synthetic dittmarite. Journal of Molecular Structure, 613 (1) 7-14 doi:10.1016/s0022-2860(02)00136-9
Localities for Dittmarite
Showing 11 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 | |
| Snow et al. (2014) |
| Palache et al. (1951) +1 other reference |
Botswana | |
| Martini (1996) +1 other reference |
Chile | |
| XRD by Joachim Lorenz |
| samples analysed by Gerhard Mohn and ... +2 other references |
| Nestola et al. (2012) | |
| forum.amiminerals.org (2016) | |
Ethiopia | |
| Tribolo et al. (2017) |
Namibia | |
| Martini (1992) |
| Mineralogical Society of America - ... |
Thailand | |
| Lenoble et al. (2006, September) |
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Punta Patache, Iquique, Iquique Province, Tarapacá, Chile