Wardsmithite
A valid IMA mineral species
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About Wardsmithite
Ward C. Smith
Formula:
Ca5Mg[B4O7]6 · 30H2O
Colour:
Colourless, white
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
1.85 - 1.88
Crystal System:
Hexagonal
Name:
Named after Ward Cromwell Smith (6 February 1906, St. Louis, Missouri, USA - 25 June 1998, Cupertino, California, USA), geologist, U.S. Geological Survey who worked with borates.
Co-Type Localities:
This page provides mineralogical data about Wardsmithite.
Unique Identifiers
Mindat ID:
4243
Long-form identifier:
mindat:1:1:4243:3
IMA Classification of Wardsmithite
Approved
IMA Formula:
Ca5Mg(B4O7)6·30H2O
Approval year:
1967
First published:
1970
Classification of Wardsmithite
6.H0.25
6 : BORATES
H : Unclassified borates
0 :
6 : BORATES
H : Unclassified borates
0 :
26.7.7.1
26 : HYDRATED BORATES CONTAINING HYDROXYL OR HALOGEN
7 : Miscellaneous
26 : HYDRATED BORATES CONTAINING HYDROXYL OR HALOGEN
7 : Miscellaneous
9.3.24
9 : Borates
3 : Borates of Ca and Sr
9 : Borates
3 : Borates of Ca and Sr
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 |
|---|---|---|
| Wsm | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Wardsmithite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Wardsmithite
Vitreous
Transparency:
Transparent
Colour:
Colourless, white
Streak:
White
Hardness:
2½ on Mohs scale
Cleavage:
Distinct/Good
{001}, good.
{001}, good.
Density:
1.85 - 1.88 g/cm3 (Measured)
Optical Data of Wardsmithite
Type:
Uniaxial (-)
RI values:
nω = 1.490(2) nε = 1.476(2)
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:
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 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.
Chemistry of Wardsmithite
Mindat Formula:
Ca5Mg[B4O7]6 · 30H2O
Element Weights:
Crystallography of Wardsmithite
Crystal System:
Hexagonal
Morphology:
anhedral with platy habit
Comment:
Point Group: n.d.; Space Group: n.d. Z = n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 13.5 Å | (100) |
| 12.3 Å | (62) |
| 6.12 Å | (55) |
| 4.721 Å | (42) |
| 2.744 Å | (26) |
| 7.73 Å | (22) |
| 2.918 Å | (20) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] |
Type Occurrence of Wardsmithite
Co-Type Localities:
General Appearance of Type Material:
fine grained nodules
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 136414, 147955, 147956.
Geological Setting of Type Material:
weathered veins of colemanite and priceite
Associated Minerals at Type Locality:
Synonyms of Wardsmithite
Other Language Names for Wardsmithite
Related Minerals - Strunz-mindat Grouping
| 6.H0.05 | Chelkarite | CaMgB2O4(Cl,OH)2 · 5H2O Or near, with Cl:OH = 3:1 |
| 6.H0.10 | Braitschite-(Ce) | (Ca,Na2)7(Ce,La)2B22O43 · 7H2O |
| 6.H0.15 | Satimolite | KNa2(Al5Mg2)[B12O18(OH)12](OH)6Cl4 · 4H2O |
| 6.H0.20 | Iquiqueite | K3Na4Mg(CrO4)B24O39(OH) · 12H2O |
| 6.H0.35 | Halurgite | Mg4[B8O13(OH)2]2 · 7H2O |
| 6.H0.40 | Ekaterinite | Ca2(B4O7)(Cl,OH)2 · 2H2O |
| 6.H0.45 | Vitimite | Ca6[B14O19](SO4)(OH)14 · 5H2O |
| 6.H0.50 | Canavesite | Mg2(HBO3)(CO3) · 5H2O |
| 6.H0.55 | Qilianshanite | NaHCO3 · H3BO3 · 2H2O |
Fluorescence of Wardsmithite
none
Other Information
Notes:
insoluble in methyl alcohol, is very slightly soluble in cold water, slightly soluble in hot water, and readily soluble in cold dilute acids.
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 Wardsmithite
mindat.org URL:
https://www.mindat.org/min-4243.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Wardsmithite
Localities for Wardsmithite
Showing 6 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.
Mexico | |
| Miranda-Gasca et al. (1998) +1 other reference | |
USA (TL) | |
| Erd et al. (1970) +1 other reference |
| Erd et al. (1970) +3 other references | |
| Erd et al. (1979) |
| U.S. Borax |
| Pemberton (1983) |
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Hard Scramble claim, Ryan, Furnace Creek Mining District, Inyo County, California, USA