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Jervisite
A valid IMA mineral species
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About Jervisite
William P. Jervis
Formula:
NaSc3+Si2O6
Colour:
Light green
Lustre:
Vitreous
Hardness:
6
Crystal System:
Monoclinic
Member of:
Name:
Named in 1982 by M. Mellini, S. Merlino, P. Orlandi, and R. Rinaldi in honour of William Paget Jervis (15 November 1832, Belgaum, India - 18 February 1906, Turin, Italy), geologist and director of the Royal Italian Industrial Museum of Turin (Museo Industriale Italiano di Torino).
Type Locality:
Isostructural with:
A Sc-bearing Na pyroxene.
Unique Identifiers
Mindat ID:
2093
Long-form identifier:
mindat:1:1:2093:6
Similar Names
| Girvasite | A valid IMA mineral species | NaCa2Mg3(PO4)3(CO3)(H2O)6 |
IMA Classification of Jervisite
Approved
IMA Formula:
NaScSi2O6
First published:
1982
Classification of Jervisite
9.DA.25
9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si2O6; pyroxene family
9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si2O6; pyroxene family
65.1.3c.6
65 : INOSILICATES Single-Width,Unbranched Chains,(W=1)
1 : Single-Width Unbranched Chains, W=1 with chains P=2
65 : INOSILICATES Single-Width,Unbranched Chains,(W=1)
1 : Single-Width Unbranched Chains, W=1 with chains P=2
14.8.12
14 : Silicates not Containing Aluminum
8 : Silicates of Group III metals other than Al
14 : Silicates not Containing Aluminum
8 : Silicates of Group III metals other than Al
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 |
|---|---|---|
| Je | 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 Jervisite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Jervisite
Optical Data of Jervisite
Type:
Biaxial (+)
RI values:
nα = 1.684(2) nβ = 1.704(6) nγ = 1.733(12)
2V:
Calculated: 69.2°
Max. Birefringence:
δ = 0.049
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:
None
Comments:
X is parallel to the c axis, Y is parallel to the b axis, and Z is parallel to the a axis.
Optical data from Vignola et al. 2019.
Optical data from Vignola et al. 2019.
Chemistry of Jervisite
Mindat Formula:
NaSc3+Si2O6
Element Weights:
Elements listed:
Common Impurities:
Ti,Al,Mn
Crystallography of Jervisite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 9.8478(2) Å, b = 9.0575(1) Å, c = 5.3409(3) Å
β = 106.82(7)°
β = 106.82(7)°
Ratio:
a:b:c = 1.087 : 1 : 0.59
Unit Cell V:
455.89 ų
Z:
4
Morphology:
Dominant forms {100} and {010}; less-developed are {141}, {221}, and {001}.
Comment:
Vignola et al. 2019
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
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
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2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
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) |
|---|---|---|---|---|---|---|---|
| 0009492 | Jervisite | Hawthorne F C, Grundy H D (1973) Refinement of the crystal structure of NaScSi2O6 Acta Crystallographica B29 2615-2616 |  | 1973 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.038 Å | (s) |
| 2.979 Å | (m) |
| 2.543 Å | (m) |
| 1.647 Å | (m) |
| 6.51 Å | (w) |
| 4.51 Å | (w) |
| 3.389 Å | (w) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites |
Type Occurrence of Jervisite
General Appearance of Type Material:
Tufts of platelets to about 0.20 x 0.08 x 0.02 mm in size.
Place of Conservation of Type Material:
Municipal Museum of Natural History, Milan, Italy, 23270.
Geological Setting of Type Material:
Granite
Associated Minerals at Type Locality:
Other Language Names for Jervisite
Relationship of Jervisite to other Species
Member of:
Other Members of Clinopyroxene Subgroup:
| Aegirine | NaFe3+Si2O6 | Mon. 2/m : B2/b |
| Aegirine-augite | (NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6 | Mon. 2/m : B2/b |
| Augite | (CaxMgyFez)(Mgy1Fez1)Si2O6 | Mon. 2/m : B2/b |
| Burnettite | CaVAlSiO6 | Mon. 2/m : B2/b |
| Clinoenstatite | MgSiO3 | Mon. 2/m : P21/c |
| Clinoferrosilite | Fe2+2Si2O6 | Mon. 2/m : P21/c |
| Colomeraite | NaTi3+Si2O6 | Mon. 2/m : B2/b |
| Davisite | CaScAlSiO6 | Mon. 2/m : B2/b |
| Diopside | CaMgSi2O6 | Mon. 2/m : B2/b |
| Esseneite | CaFe3+[AlSiO6] | Mon. 2/m : B2/b |
| Grossmanite | CaTi3+ AlSiO6 | Mon. 2/m : B2/b |
| Hedenbergite | CaFe2+Si2O6 | Mon. 2/m : B2/b |
| Jadeite | Na(Al,Fe3+)Si2O6 | Mon. 2/m : B2/b |
| Johannsenite | CaMn2+Si2O6 | Mon. 2/m : B2/b |
| Kanoite | Mn2+MgSi2O6 | Mon. 2/m : P21/c |
Seula mine, Mount Camoscio, Oltrefiume, Baveno, Verbano-Cusio-Ossola Province, Piedmont, Italy