Numanoite
A valid IMA mineral species
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About Numanoite
Formula:
Ca4Cu(B4O6(OH)6)(CO3)2
Colour:
bluish green
Lustre:
Vitreous
Hardness:
4½
Specific Gravity:
2.96
Crystal System:
Monoclinic
Name:
Named in honor of Dr. Tadayuki Numano (沼野 忠之) (1931 Okayama pref., Japan - 2001), professor at Okayama University.
Unique Identifiers
Mindat ID:
29100
Long-form identifier:
mindat:1:1:29100:6
Similar Names
| Naumannite | A valid IMA mineral species - grandfathered | Ag2Se |
| Naumannite (of Koksharov) | A synonym of Rutile |
IMA Classification of Numanoite
Approved
IMA Formula:
Ca4Cu2+B4O6(OH)6(CO3)2
Approval year:
2005
First published:
2007
Type description reference:
Classification of Numanoite
6.DA.40
6 : BORATES
D : Tetraborates
A : Neso-tetraborates
6 : BORATES
D : Tetraborates
A : Neso-tetraborates
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 |
|---|---|---|
| Num | 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 Numanoite
Vitreous
Transparency:
Translucent
Colour:
Bluish green
Comment:
Varies from quite intense to very pale, almost colorless, partly depending on thickness of the numanoite zone.
Hardness:
4½ on Mohs scale
Hardness:
VHN25=290 - 464 kg/mm2 - Vickers
Hardness Data:
Measured
Cleavage:
Perfect
{100} {110}
{100} {110}
Density:
2.96 g/cm3 (Measured) 2.96 g/cm3 (Calculated)
Optical Data of Numanoite
Type:
Biaxial (-)
RI values:
nα = 1.618(2) nβ = 1.658(2) nγ = 1.672(2)
2V:
Calculated: 60°
Max. Birefringence:
δ = 0.054
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.
Chemistry of Numanoite
Mindat Formula:
Ca4Cu(B4O6(OH)6)(CO3)2
Element Weights:
Crystallography of Numanoite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 17.794 Å, b = 8.381 Å, c = 4.4494 Å
β = 102.42°
β = 102.42°
Ratio:
a:b:c = 2.123 : 1 : 0.531
Unit Cell V:
648.02 ų (Calculated from Unit Cell)
Z:
2
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.57 Å | (100) |
| 2.671 Å | (84) |
| 2.727 Å | (68) |
| 1.887 Å | (52) |
| 2.272 Å | (48) |
| 2.899 Å | (44) |
| 1.698 Å | (34) |
Reference:
Comments:
resembles borcarite pattern
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) |
Type Occurrence of Numanoite
General Appearance of Type Material:
Bluish green central zone in colorless borcarite crystals.
Place of Conservation of Type Material:
National Science Museum (Japan), specimen # M28813.
Geological Setting of Type Material:
Borate-bearing low-Fe calc-silicate skarn.
Associated Minerals at Type Locality:
Reference:
Synonyms of Numanoite
Other Language Names for Numanoite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 6.DA.10 | Borax | Na2(B4O5)(OH)4 · 8H2O |
| 6.DA.15 | Tincalconite | Na2(B4O7) · 5H2O |
| 6.DA.20 | Hungchaoite | Mg(B4O7) · 9H2O |
| 6.DA.25 | Roweite | Ca2Mn2+2B4O7(OH)6 |
| 6.DA.25 | Fedorovskite | Ca2Mg2B4O7(OH)6 |
| 6.DA.30 | Hydrochlorborite | Ca4B8O15Cl2 · 21H2O |
| 6.DA.35 | Uralborite | Ca2[B3O3(OH)5 · OB(OH)3] |
| 6.DA.40 | Borcarite | Ca4Mg(B4O6(OH)6)(CO3)2 |
| 6.DA.60 | Fontarnauite | (Na,K)2(Sr,Ca)(SO4)[B5O8(OH)] · 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 Numanoite
mindat.org URL:
https://www.mindat.org/min-29100.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Numanoite
Reference List:
Ohnishi, M., Kusachi, I., Kobayashi, S., Yamakawa, J., Tanabe, M., Kishi, S., Yasuda, T. (2007) Numanoite, Ca4CuB4O6(OH)6(CO3)2, a new mineral species, the Cu analogue of borcarite from the Fuka mine, Okayama Prefecture, Japan. The Canadian Mineralogist, 45 (2) 307-315 doi:10.2113/gscanmin.45.2.307
Poirier, G., Piilonen, P. C. (2007) New Mineral Names. American Mineralogist, 92 (10) 1776-1779 doi:10.2138/am.2007.503
Localities for Numanoite
Showing 1 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.
Japan (TL) | |
| Ohnishi (2005) +1 other reference |
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Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan