Itsiite
A valid IMA mineral species
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About Itsiite
Gun claim area overview
Gun claim, Wilson Lake, Itsi Mountain, Watson Lake mining district, Yukon, Canada
Gun claim, Wilson Lake, Itsi Mountain, Watson Lake mining district, Yukon, Canada
Formula:
Ba4Ca2[Si8B4O28]◻
may also be given as Ba2Ca(BSi2O7)2
Colour:
Colorless and light blue to medium greenish-blue
Lustre:
Vitreous
Hardness:
5½
Specific Gravity:
3.644 (Calculated)
Crystal System:
Tetragonal
Member of:
Name:
Itsiite is named for the Itsi Mountain Range, a spectacular, glaciated, multi-peaked massif within the Selwyn Mountains proper. “Itsi” means “wind” in the language of the Kaska, a First Nations people of the area.
Structurally related to hyalotekite and kapitsaite-(Y). The B2◻ (or B2-vacancy-) analogue of hyalotekite.
Unique Identifiers
Mindat ID:
45994
Long-form identifier:
mindat:1:1:45994:7
IMA Classification of Itsiite
Approved
IMA Formula:
Ba2Ca(BSi2O7)2
Approval year:
2013
First published:
2014
Classification of Itsiite
9.CH.05
9 : SILICATES (Germanates)
C : Cyclosilicates
H : [Si4O12]8- 4-membered double rings
9 : SILICATES (Germanates)
C : Cyclosilicates
H : [Si4O12]8- 4-membered double rings
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 |
|---|---|---|
| Its | 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 Itsiite
Vitreous
Transparency:
Transparent
Colour:
Colorless and light blue to medium greenish-blue
Streak:
White
Hardness:
5½ on Mohs scale
Comment:
Based on scratch test
Tenacity:
Brittle
Cleavage:
Perfect
on {001}
on {001}
Fracture:
Splintery
Density:
3.644 g/cm3 (Calculated)
Comment:
Could not be measured because the crystals are generally heavily included with cerchiaraite-(Fe)
Optical Data of Itsiite
Type:
Uniaxial (-)
RI values:
nω = 1.623(1) nε = 1.619(1)
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 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:
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.
Pleochroism:
Non-pleochroic
Chemistry of Itsiite
Mindat Formula:
Ba4Ca2[Si8B4O28]◻
may also be given as Ba2Ca(BSi2O7)2
may also be given as Ba2Ca(BSi2O7)2
Element Weights:
Crystallography of Itsiite
Crystal System:
Tetragonal
Class (H-M):
42m - Scalenohedral
Space Group:
I42m
Setting:
I42m
Cell Parameters:
a = 10.9515(5) Å, c = 10.3038(7) Å
Ratio:
a:c = 1 : 0.941
Unit Cell V:
1235.79 ų
Z:
4
Morphology:
Tetragonal plates flattened on {001} and exhibit the forms {001}, {101}, and {112}; ; the forms {101} and {112} are generally striated.
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
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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) |
|---|---|---|---|---|---|---|---|
| 0020420 | Itsiite | Kampf A R, Peterson R C, Joy B R (2014) Itsiite, Ba2Ca(BSi2O7)2, a new mineral species from Yukon, Canada: description and crystal structure The Canadian Mineralogist 52 401-407 | 2014 | Itsi Range, Yukon Territory, Canada | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.764 Å | (100) |
| 3.446 Å | (60) |
| 3.100 Å | (51) |
| 2.899 Å | (96) |
| 2.279 Å | (44) |
| 2.145 Å | (69) |
| 1.758 Å | (43) |
Locality:
Reference:
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Type Occurrence of Itsiite
General Appearance of Type Material:
As intergrowths of tetragonal plates up to 1 mm across. Crystals of Itsiite are commonly heavily included with cerchiaraite-(Fe)
Place of Conservation of Type Material:
Type material is deposited in the collections of the Natural History Museum of Los Angeles County, Los Angeles, California, USA, catalogue number 64072
Geological Setting of Type Material:
Ba-rich skarn deposit associated with a quartz monzonite. Itsiite found in low temperature, late-stage veins
Associated Minerals at Type Locality:
Synonyms of Itsiite
Other Language Names for Itsiite
Relationship of Itsiite to other Species
Member of:
Other Members of Hyalotekite Group:
| Guastoniite-(Y) | Pb4(YCa)(Si8B4O28)F | Tric. 1 : P1 |
| Hyalotekite | (Ba,Pb,K)4(Ca,Y)2(B,Be)2(Si,B)2Si8O28(F,Cl) | Tric. 1 : P1 |
| Kapitsaite-(Y) | (Ba,K,Pb)4(Y,Ca)2Si8(B,Si)4O28F | Tric. 1 : P1 |
| Khvorovite | (Pb,Ba,K)4Ca2[Si8B2(Si,B)2O28]F | Tric. |
Common Associates
Associations Based on Photo Data:
| 3 photos of Itsiite associated with Cerchiaraite-(Fe) | Ba4Fe3+4O3(OH)3(Si4O12)[Si2O3(OH)4]Cl |
| 3 photos of Itsiite associated with Gillespite | BaFe2+Si4O10 |
| 3 photos of Itsiite associated with Pellyite | Ba2CaFe2+2Si6O17 |
| 3 photos of Itsiite associated with Witherite | BaCO3 |
| 2 photos of Itsiite associated with Hedenbergite | CaFe2+Si2O6 |
| 1 photo of Itsiite associated with Pyrite | FeS2 |
Related Minerals - Strunz-mindat Grouping
| 9.CH.05 | Khvorovite | (Pb,Ba,K)4Ca2[Si8B2(Si,B)2O28]F |
| 9.CH.05 | Guastoniite-(Y) | Pb4(YCa)(Si8B4O28)F |
| 9.CH.05 | Kapitsaite-(Y) | (Ba,K,Pb)4(Y,Ca)2Si8(B,Si)4O28F |
| 9.CH.05 | Hyalotekite | (Ba,Pb,K)4(Ca,Y)2(B,Be)2(Si,B)2Si8O28(F,Cl) |
| 9.CH.10 | Arapovite | (K1-x◻x)(Ca,Na)2U4+Si8O20 (x ~ 0.5) |
| 9.CH.10 | Steacyite | K0.3(Na,Ca)2ThSi8O20 |
| 9.CH.10 | Turkestanite | (K,◻)(Ca,Na)2ThSi8O20 · nH2O |
| 9.CH.10 | Iraqite-(La) | KCa2(La,Ce,Th)Si8O20 |
Fluorescence of Itsiite
non-fluorescent
Other Information
Notes:
Slowly decompose in concentrated HCl (about 1 h) and are unreactive in concentrated H2SO4 (days).
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 Itsiite
mindat.org URL:
https://www.mindat.org/min-45994.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 Itsiite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) New minerals and nomenclature modifications approved in 2013. CNMNC Newsletter No 18. Mineralogical Magazine, 77 (8) 3249-3258 doi:10.1180/minmag.2013.077.8.15
Localities for Itsiite
Showing 2 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.
Canada | |
| Kampf et al. (2014) +1 other reference |
| Kampf et al. (2014) |
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Gun claim, Wilson Lake, Itsi Mountain, Watson Lake mining district, Yukon, Canada