Maruyamaite
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Formula:
K(MgAl2)(Al5Mg)(BO3)3(Si6O18)(OH)3O
Colour:
Pale brown to brown
Lustre:
Vitreous
Hardness:
7
Specific Gravity:
3.081 (Calculated)
Crystal System:
Trigonal
Member of:
The first IMA-approved K member of the tourmaline group, found in high-pressure rocks. Related to oxy-dravite, of which it is the K analogue.
See also UM2000-64-SiO:BFeHKMg.
Supposed to originate near the peak pressure conditions of UHP metamorphism, within the diamond stability field.
See also UM2000-64-SiO:BFeHKMg.
Supposed to originate near the peak pressure conditions of UHP metamorphism, within the diamond stability field.
Classification of Maruyamaite
Approved
Approval Year:
2013
Physical Properties of Maruyamaite
Vitreous
Colour:
Pale brown to brown
Streak:
White to very pale-brown
Hardness:
7 on Mohs scale
Comment:
~7
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
No observable parting
Density:
3.081 g/cm3 (Calculated)
Optical Data of Maruyamaite
Type:
Uniaxial (-)
RI values:
nω = 1.632 - 1.636 nε = 1.650 - 16.520
Max Birefringence:
δ = 0.018

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Very High
Pleochroism:
Visible
Comments:
O = darkish brown, E = pale brown
Chemical Properties of Maruyamaite
Formula:
K(MgAl2)(Al5Mg)(BO3)3(Si6O18)(OH)3O
Crystallography of Maruyamaite
Crystal System:
Trigonal
Class (H-M):
3m - Ditrigonal Pyramidal
Space Group:
R3m
Setting:
R3m
Cell Parameters:
a = 15.955(1) Å, c = 7.227(1) Å
Ratio:
a:c = 1 : 0.453
Unit Cell V:
1593 ų
Z:
3
Morphology:
Anhedral to euhedral grains up to 2 mm across
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
6.415 | (23) |
4.237 | (59) |
3.995 | (69) |
3.498 | (42) |
2.974 | (85) |
2.581 | (100) |
2.046 | (54) |
1.923 | (36) |
Comments:
From Type Description.
Type Occurrence of Maruyamaite
General Appearance of Type Material:
Anhedral to euhedral grains up to 2 mm across, embedded in a matrix of anhedral quartz and K-feldspar. May contain inclusions of microdiamonds.
Place of Conservation of Type Material:
Type material is deposited in the collections of the National Museum of Nature and Science, Tsukuba, Japan, registered number NSMMF15696
Geological Setting of Type Material:
Ultrahigh-pressure quartzofeldspathic gneisses
Associated Minerals at Type Locality:
Synonyms of Maruyamaite
Relationship of Maruyamaite to other Species
Member of:
Other Members of this group:
Adachiite | CaFe3Al6(Si5AlO18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Bosiite | NaFe3+3(Al4Mg2)(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Chromium-dravite | Na(Mg3)Cr3+6(Si6O18)(BO3)3(OH)3(OH) | Trig. |
Chromo-alumino-povondraite | Na(Cr3)(Al4Mg2)(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Darrellhenryite | Na(LiAl2)Al6(BO3)3Si6O18(OH)3O | Trig. 3m : R3m |
Dravite | Na(Mg3)Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Elbaite | Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Feruvite | Ca(Fe2+)3MgAl5(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Fluor-buergerite | Na(Fe3+3)Al6(Si6O18)(BO3)3O3F | Trig. 3m : R3m |
Fluor-dravite | Na(Mg3)Al6(Si6O18)(BO3)3(OH)3F | Trig. 3m : R3m |
Fluor-elbaite | Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3F | Trig. 3m : R3m |
Fluor-feruvite | Ca(Fe2+)3MgAl5(Si6O18)(BO3)3(OH)3F | |
Fluor-liddicoatite | Ca(Li2Al)Al6(Si6O18)(BO3)3(OH)3F | Trig. 3m : R3m |
Fluor-schorl | Na(Fe2+3)Al6(Si6O18)(BO3)3(OH)3F | Trig. 3m : R3m |
Fluor-tsilaisite | Na(Mn2+)3Al6(Si6O18)(BO3)3(OH)3F | Trig. 3m : R3m |
Fluor-uvite | Ca(Mg3)MgAl5(Si6O18)(BO3)3(OH)3F | Trig. 3m : R3m |
Foitite | (□,Na)(Fe2+2Al)Al6(Si6O18)(BO3)3(OH)3OH | Trig. 3m : R3m |
Liddicoatite | Ca(Li2Al)Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Lucchesiite | CaFe2+3 Al6(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Luinaite-(OH) | Na(Fe2+)3Al6(Si6O18)(BO3)3(OH)3(OH) | Mon. m : Bm |
Magnesio-foitite | (□,Na)(Mg2Al)Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. |
Olenite | Na(Al3)Al6(Si6O18)(BO3)3O3(OH) | Trig. |
Oxy-chromium-dravite | Na(Cr)3(Cr4Mg2)(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Oxy-dravite | Na(MgAl2)MgAl5(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Oxy-foitite | □(Fe2+Al2)Al6(Si6O18)(BO3)3(OH)3O | Trig. 3m (3 2/m) : R3m |
Oxy-rossmanite | ☐(LiAl2)Al6(Si6O18)(BO3)3(OH)3O | |
Oxy-schorl | Na(Fe2+2Al)Al6(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Oxy-uvite | CaMg3Al6(Si6O18)(BO3)3(OH)3O | |
Oxy-vanadium-dravite | Na(V)3(V4Mg2)Si6O18(BO3)3(OH)3O | Trig. 3m : R3m |
Povondraite | NaFe3+3(Mg2Fe3+4)(Si6O18)(BO3)3(OH)3O | Trig. |
Rossmanite | ☐(LiAl2)Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Schorl | Na(Fe2+3)Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
Tsilaisite | Na(Mn2+)3Al6(Si6O18)(BO3)3(OH)3(OH) | Trig. 3m : R3m |
UM2000-64-SiO:BFeHKMg | K, Mg, Fe, Si, B, O, H | |
Unnamed (Pb-dominant Tourmaline) | (Pb,Na)(Li,Al)3Al6(Si6O18)(BO3)3(OH)3(F,OH) | |
Uvite Series | Ca(Mg3)MgAl5(Si6O18)(BO3)3(OH)3(F/OH) | Trig. 3m : R3m |
Vanadio-oxy-chromium-dravite | Na(V)3(Cr4Mg2)(Si6O18)(BO3)3(OH)3O | Trig. 3m : R3m |
Vanadio-oxy-dravite | NaV3(Al4Mg2)(Si6O18)(BO3)3(OH)3O | Trig. 3m |
Fluorescence of Maruyamaite
Non-fluorescent
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.
References for Maruyamaite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Lussier, A., Ball, N.A., Hawthorne, F.C., Henry, D.J., Shimizu, R., Ogasawara, Y. and Ota, T. (2014) Maruyamaite, IMA 2013- 123. CNMNC Newsletter No. 20, June 2014, page 550; Mineralogical Magazine, 78, 549-558.
Hawthorne, F.C., Lussier, A.J., Ball, N.A., Henry, D.J., Shimizu, R., Ogasawara, Y., Ota, T. (2016): Maruyamaite, K(MgAl2)(Al5Mg)Si6O18(BO3)3(OH)3O, from the ultrahigh-pressure Kokchetav massif, northern Kazakhstan: Description and crystal structure. American Mineralogist, 101, 355-361.
Internet Links for Maruyamaite
mindat.org URL:
https://www.mindat.org/min-46075.html
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Localities for Maruyamaite
Locality List




All localities listed without proper references should be considered as questionable.
Kazakhstan (TL) | |
| Lussier, A., Ball, N.A., Hawthorne, F.C., Henry, D.J., Shimizu, R., Ogasawara, Y. and Ota, T. (2014) Maruyamaite, IMA 2013- 123. CNMNC Newsletter No. 20, June 2014, page 550; Mineralogical Magazine, 78, 549-558. |