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Juanite
A valid IMA mineral species - grandfathered - questionable
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About Juanite
Formula:
Ca10Mg4Al2Si11O39 · 4H2O or near
Colour:
Nearly white to pistachio-green
Lustre:
Dull
Hardness:
5½
Specific Gravity:
3.01 - 3.3
Crystal System:
Orthorhombic
Name:
Named for the San Juan Mountains, Colorado, USA, that include the type locality.
Unique Identifiers
Mindat ID:
2119
Long-form identifier:
mindat:1:1:2119:3
Similar Names
| Guanite | A synonym of Struvite | |
| Janite | ||
| Jennite | A valid IMA mineral species | Ca9(Si3O9)2(OH)8 · 8H2O |
| Johnite | A synonym of Turquoise | |
| Juabite | A valid IMA mineral species | CaCu10(TeO3)4(AsO4)4(OH)2 · 4H2O |
| Juanitaite | A valid IMA mineral species | (Cu,Ca,Fe)10Bi(AsO4)4(OH)11 · 2H2O |
| Jungite | A valid IMA mineral species | Ca2Zn4Fe83+(PO4)9(OH)9 · 16H2O |
| Junitoite | A valid IMA mineral species | CaZn2Si2O7 · H2O |
| Junoite | A valid IMA mineral species | Cu2Pb3Bi8(S,Se)16 |
| Juonniite | A valid IMA mineral species | CaMgSc(PO4)2(OH) · 4H2O |
| Suanite | A valid IMA mineral species - grandfathered | Mg2[B2O5] |
IMA Classification of Juanite
Approved, 'Grandfathered' (first described prior to 1959), Questionable
IMA Formula:
Ca10(Mg,Fe2+)4(Si,Al)13(O,OH)39·4H2O
Classification of Juanite
9.HA.70
9 : SILICATES (Germanates)
H : Unclassified silicates
A : With Alkali and Alkali-earth Elements
9 : SILICATES (Germanates)
H : Unclassified silicates
A : With Alkali and Alkali-earth Elements
78.7.6.1
78 : Unclassified Silicates
7 :
78 : Unclassified Silicates
7 :
16.11.6
16 : Silicates Containing Aluminum and other Metals
11 : Aluminosilicates of Ca and Mg with or without alkalis
16 : Silicates Containing Aluminum and other Metals
11 : Aluminosilicates of Ca and Mg with or without alkalis
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 |
|---|---|---|
| Jn | 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 Juanite
Dull
Transparency:
Translucent
Colour:
Nearly white to pistachio-green
Hardness:
5½ on Mohs scale
Density:
3.01 - 3.3 g/cm3 (Measured)
Optical Data of Juanite
Type:
Biaxial (+)
RI values:
nα = 1.640(3) nβ = 1.642 nγ = 1.647(3)
2V:
Measured: 50° , Calculated: 66°
Max. Birefringence:
δ = 0.007
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 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:
relatively weak
Chemistry of Juanite
Mindat Formula:
Ca10Mg4Al2Si11O39 · 4H2O or near
Element Weights:
Common Impurities:
Fe,Mn,Na,K,P
Crystallography of Juanite
Crystal System:
Orthorhombic
Morphology:
slender fibers in sheaflike aggregates, to about 1 mm; massive.
Comment:
Orthorhombic (?). Point Group: n.d.; Space Group: n.d. Z = n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.27 Å | (100) |
| 2.98 Å | (100) |
| 1.93 Å | (100) |
| 2.90 Å | (90) |
| 1.97 Å | (80) |
| 3.58 Å | (50) |
| 3.41 Å | (50) |
Type Occurrence of Juanite
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts; National Museum of Natural History, Washington, D.C., USA, 105990.
Associated Minerals at Type Locality:
Other Language Names for Juanite
Common Associates
Associations Based on Photo Data:
| 2 photos of Juanite associated with Alumoåkermanite | (CaNa)Al[Si2O7] |
| 2 photos of Juanite associated with Cebollite | Ca5Al2(SiO4)3(OH)4 |
Related Minerals - Strunz-mindat Grouping
| 9.HA. | Shinichengite | Ca5[BSi2O7(OH)2]2 · 6H2O |
| 9.HA. | Kalyuzhnyite-(Ce) | NaKCaSrCeTi(Si8O21)OF(H2O)3 |
| 9.HA. | Moragite | Ca3TiSi2(Al2Si)O14 |
| 9.HA.05 | Ertixiite | Na2Si4O9 |
| 9.HA.10 | Kenyaite | Na2Si22O41(OH)8 · 6H2O |
| 9.HA.20 | Wawayandaite | Ca6Mn2BBe9Si6O23(OH,Cl)15 |
| 9.HA.25 | Magbasite | KBaFe3+Mg7Si8O22(OH)2F6 |
| 9.HA.35 | Demagistrisite | BaCa2Mn3+4(Si3O10)(Si2O7)(OH)4 · 3H2O |
| 9.HA.37 | Donwilhelmsite | CaAl4Si2O11 |
| 9.HA.40 | Kasatkinite | Ba2Ca8B5Si8O32(OH)3 · 6H2O |
| 9.HA.40 | 'Igumnovite' | Ca3Al2[SiO4]2[◻Cl4] |
| 9.HA.42 | Paqueite | Ca3TiSi2(Al,Ti,Si)3O14 |
| 9.HA.42 | Qeltite | Ca3TiSi2(Fe3+2Si)O14 |
| 9.HA.45 | Rippite | K2(Nb,Ti)2(Si4O12)O(O,F) |
| 9.HA.47 | Zagamiite | CaAl2Si3.5O11 |
| 9.HA.50 | Rudenkoite | Sr3(Al3.5Si3.5)O10(OH,O)8Cl2 · H2O |
| 9.HA.50 | 'α-Carnegieite' | NaAlSiO4 |
| 9.HA.52 | 'Atheriastite' | near Ca5MgFeAl6Si8O32 · 5H2O |
| 9.HA.55 | 'Foshallasite' | Ca3[Si2O7] · 3H2O(?) |
| 9.HA.57 | 'Bhreckite' | |
| 9.HA.60 | Nagelschmidtite | Ca7(SiO4)2(PO4)2 |
| 9.HA.65 | Caryochroite | [Na(Sr0.5Ca0.5)Mg]3[Fe3+8Mn(Fe2+0.5◻0.5)]10(Ti2Si12O37)(OH)14(H2O)3 |
| 9.HA.75 | Tacharanite | Ca12Al2Si18O33(OH)36 |
| 9.HA.80 | Oyelite | Ca10Si8B2O29 · 12.5H2O |
| 9.HA.85 | Denisovite | K14+x(Ca,Na,Mn,Fe)48[Si60O162]F16(Ox,OH4-x) · 2H2O |
| 9.HA.90 | Tiettaite | K4Na12Fe3+Si16O41(OH)4 · 2H2O |
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 Juanite
mindat.org URL:
https://www.mindat.org/min-2119.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Juanite
Localities for Juanite
Showing 4 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.
Russia | |
| Pavel M. Kartashov (n.d.) |
| Liferovich et al. (1998) |
USA (TL) | |
| Larsen (1942) +1 other reference |
Quick NavTopAbout JuaniteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionType Occurrence Other LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Kovdor Massif, Kovdorsky District, Murmansk Oblast, Russia