Where it forms, where it's found
- Geological setting
Fissure-fillings in serpentinite
- Type locality
- Nakauri mine
- Shinshiro city
- Aichi Prefecture
- Japan
34.8494°, 137.5521°
13recorded occurrences
Physical
- Transparency
- Translucent
- Colour
- Translucent blue
- Density
- 2.39 g/cm³
Optical
- Optical type
- Biaxial (-) · 2V measured = 60 – 70° · 2V calc = 65°
- Refractive index
- 1.585 – 1.618
- Surface relief
- Moderate
- Principal indices
- nα 1.585 – 1.597 · nβ 1.604 – 1.612 · nγ 1.612 – 1.618
- Pleochroism
- Visible
X = colorless, Y = very light greenish blue,Z = pale sky-blue to very light blue.
- Dispersion
- small
Δ = 0Δmax
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation240 nm
Order1st order
XPL colour
Crystallography
- Cell parameters
- a = 14.585 Å · b = 11.47 Å · c = 16.22 Å
- Ratio a:b:c
- 1 : 0.786 : 1.112
- Z
- 2
- Morphology
Crystals are fibers, to 3 mm, in sprays and aggregates.
- Type-locality form
Bundled aggregates of very small slender to fibrous crystals, whose sizes are less than about 0.2 mm in length, 0.006 mm in width.
- Comment
Point Group: n.d; Space Group: n.d.
Chemical composition
Synonyms
- Cuprohydromagnesite
- IMA1976-016
- Nakauriiet
In other languages
- German
- Nakauriit
- Italian
- Nakauriite
- Japanese
- 中宇利石
Classification
Strunz
10th ed.7.DG.30
- 7SulfatesClass
- 7.DSulfates (selenates, etc.) with additional anions, with H2ODivision
- 7.DGWith large and medium-sized cations; with NO3, CO3, B(OH)4, SiO4 or IO3Group
- 7.DG.30NakauriiteSpecies
Dana
8th ed.32.04.01.01
- 32Compound SulfatesClass
- 32.04Hydrated Compound Sulfates containing Hydroxyl or HalogenType
- 32.04.01— unnamed intermediate level —Group
- 32.04.01.01NakauriiteSpecies
CIM
—12.2.6
- 12Carbonates with other anionsClass
- 12.2Carbonates with sulphateGroup
- 12.2.6NakauriiteSpecies
Literature, links & citation
Citations
- —Peacor D.R., Simmons W.B., Jr., Essene E.J., Heinrich E.W. (1982): New data on and discreditation of "texasite", "albrittonite", "cuproartinite","cuprohydromagnesite", and "yttromicrolite" with corrected data on nickelbischofite, rowlandite and yttrocrasite. American Mineralogist. 67, 156-169. http://www.minsocam.org/ammin/AM67/AM67_156.pdf
- 1976Suzuki, Jujin, Ito, Masahiro, Sugiura, Tsutomu (1976) A new copper sulfate-carbonate hydroxide hydrate mineral, (Mn,Ni,Cu)8(SO4)4(CO3)(OH)6·48H2O, from Nakauri, Aichi Prefecture, Japan. The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists, 71 (7) 183-192 doi:10.2465/ganko1941.71.183 DOI: 10.2465/ganko1941.71.183
- 1977Fleischer, Michael, Cabri, Louis J., Nickel, Ernest H., Pabst, Adolf (1977) New Mineral Names. American Mineralogist, 62 (5-6) 593-600
- 1982American Mineralogist (1982): 67: 167.
- 1983Braithwaite, R. S. W., Pritchard, R. (1983) Nakauriite from Unst, Shetland. Mineralogical Magazine, 47 (342) 84-85 doi:10.1180/minmag.1983.047.342.17 DOI: 10.1180/minmag.1983.047.342.17
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Nakauriite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/nakauriite-2948},
note = {Accessed 2026-05-11}
}