Bostwickite
A valid IMA mineral species
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About Bostwickite
Richard Bostwick
Formula:
CaMn3+6Si3O16 · 7H2O
Colour:
Brownish red
Lustre:
Sub-Vitreous, Greasy, Silky, Sub-Metallic
Hardness:
1
Specific Gravity:
2.93
Crystal System:
Orthorhombic
Name:
Named in 1983 by Pete J. Dunn and Peter B. Leavens in honor of Richard "Dick" Bostwick [January 19, 1943 - ], author, editor, lecturer, a fellow of the International Centre for Diffraction Data (ICDD), and prominent mineral collector, with a particular emphasis concerning fluorescent minerals. He is a past President of the Franklin-Ogdensburg Mineralogical Society, board member of the Franklin Mineral Museum, former hard rock miner in the Sterling Mine, Ogdensberg, New Jersey, USA, and regional Vice President of the Fluorescent Mineral Society. He is a frequent lecturer throughout the U.S.A. Dick is a life member of the National Mining Hall of Fame and Museum, an honorary member of the New York Mineralogical Club, and is in the Fluorescent Mineral Society’s Hall of Fame.
Brownish-red bronzey acicular crystals.
Unique Identifiers
Mindat ID:
731
Long-form identifier:
mindat:1:1:731:9
IMA Classification of Bostwickite
Approved
IMA Formula:
CaMn3+6Si3O16·7H2O
Approval year:
1983
Classification of Bostwickite
9.HC.10
9 : SILICATES (Germanates)
H : Unclassified silicates
C : With Mn, Fe
9 : SILICATES (Germanates)
H : Unclassified silicates
C : With Mn, Fe
78.7.1.1
78 : Unclassified Silicates
7 :
78 : Unclassified Silicates
7 :
14.18.24
14 : Silicates not Containing Aluminum
18 : Silicates of Mn and Na, K, Mg, Ca or Fe
14 : Silicates not Containing Aluminum
18 : Silicates of Mn and Na, K, Mg, Ca or Fe
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 |
|---|---|---|
| Btw | 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 Bostwickite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Bostwickite
Sub-Vitreous, Greasy, Silky, Sub-Metallic
Transparency:
Transparent, Translucent
Comment:
submetallic on prism surfaces.
Colour:
Brownish red
Streak:
White
Hardness:
1 on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
2.93(10) g/cm3 (Measured)
Optical Data of Bostwickite
Type:
Biaxial (-)
RI values:
nα = 1.775 nβ = 1.798 nγ = 1.800
2V:
Measured: 25° , Calculated: 32°
Birefringence:
0.025
Max. Birefringence:
δ = 0.025
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:
Very 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 strong
Optical Extinction:
Parallel
Pleochroism:
Strong
Comments:
X = Y = red-brown; Z = yellow-brown.
Chemistry of Bostwickite
Mindat Formula:
CaMn3+6Si3O16 · 7H2O
Element Weights:
Common Impurities:
Al,Fe,As,Mg
Crystallography of Bostwickite
Crystal System:
Orthorhombic
Morphology:
acicular in slightly divergent groups
Comment:
Orthorhombic (?). Point Group: n.d; Space Group: n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 11.30 Å | (100) |
| 8.19 Å | (10) |
| 6.03 Å | (2) |
| 5.57 Å | (2) |
| 4.575 Å | (5) |
| 3.951 Å | (10) |
| 3.826 Å | (5) |
| 3.786 Å | (5) |
| 3.548 Å | (30) |
| 3.238 Å | (15) |
| 3.110 Å | (2) |
| 2.898 Å | (30) |
| 2.718 Å | (15) |
| 2.567 Å | (40) |
| 2.475 Å | (20) |
| 2.442 Å | (20) |
| 2.262 Å | (25) |
| 2.238 Å | (25) |
| 2.094 Å | (15) |
| 2.074 Å | (10) |
| 1.951 Å | (5) |
| 1.863 Å | (5) |
| 1.794 Å | (15) |
| 1.679 Å | (10) |
| 1.634 Å | (5) |
| 1.599 Å | (10) |
| 1.501 Å | (10) |
| 1.470 Å | (25) |
Reference:
Comments:
35-616
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Type Occurrence of Bostwickite
General Appearance of Type Material:
As divergent sprays of bladed crystals, commonly composed of tiny microcrystals, to 250 μm
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts, 125617{125620; National Museum of Natural History, Washington, D.C., USA, C4222.
Geological Setting of Type Material:
Deposited with gray fluorite on fractures in silicate and oxide zinc ore
Associated Minerals at Type Locality:
Synonyms of Bostwickite
Other Language Names for Bostwickite
Common Associates
Associations Based on Photo Data:
| 1 photo of Bostwickite associated with Kittatinnyite | Ca2Mn2Mn(SiO4)2(OH)4 · 9H2O |
Related Minerals - Strunz-mindat Grouping
| 9.HC.05 | Erlianite | (Fe,Mg)4(Fe,V)2Si6O15(OH,O)8 |
| 9.HC.20 | 'Almbosite' | Fe2+5Fe3+4V6+4Si3O27 |
| 9.HC.25 | 'Aquacreptite (of Shepard)' | Mg4Fe2Si6O19 · 8H2O with some Al2O3, or near |
| 9.HC.30 | 'Farallonite' | 2MgO · W2O5 · SiO2 · nH2O? |
| 9.HC.35 | 'Hokoite' | Mn2+Mn3+2SiO6 · H2O |
| 9.HC.40 | 'Polyhydrite' |
Fluorescence of Bostwickite
Not fluorescent in UV
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 Bostwickite
mindat.org URL:
https://www.mindat.org/min-731.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Bostwickite
Localities for Bostwickite
Showing 1 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.
USA (TL) | |
| Dunn & Leavens (1983) +2 other references |
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Taylor Mine, Franklin Mine, Franklin, Sussex County, New Jersey, USA