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Henmilite

A valid IMA mineral species

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Photos of Henmilite (88)

Henmilite Gallery Search Photos of Henmilite

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Henmilite

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite, etc.

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite, etc.

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

Henmilite

Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

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About HenmiliteHide

Image of Prof. Henmi and his daughter, Dr. Henmi

Formula:

Ca₂Cu[B(OH)₄]₂(OH)₄

Colour:

Blue-violet

Lustre:

Vitreous

Hardness:

1½ - 2

Specific Gravity:

2.51

Crystal System:

Triclinic

Name:

Named for Professor Kitinosuke Henmi (逸見吉之助) (28 June 1919, Okayama City, Japan - 11 November 1997) and his daughter Dr. Chiyoko Henmi (逸見千代子) (1949 – 2018), Department of Earth Science, Okayama University, in recognition of their work on skarn minerals from Fuka. The mineral chiyokoite is also named after Chiyoko Henmi.

Type Locality:

ⓘ Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

This page provides mineralogical data about Henmilite.

Unique IdentifiersHide

Mindat ID:

1866

Long-form identifier:

mindat:1:1:1866:7

GUID
(UUID V4):

f04d6ab8-8533-4716-8aac-7499cc234b74

IMA Classification of HenmiliteHide

IMA status:

Approved

Approval year:

1981

First published:

1986

Type description reference:

Nakai, I., Okada, H., Masutomi, K., Koyama, E., Nagashima, K. (1986) Henmilite, Ca₂Cu(OH)₄[B(OH)₄]₂, a new mineral from Fuka, Okayama Prefecture, Japan. American Mineralogist, 71 (9-10) 1234-1239

Classification of HenmiliteHide

Strunz-mindat (2024):

6.AC.30

6 : BORATES
A : Monoborates
C : B(O,OH)₄, without and with additional anions; 1(T), 1(T)+OH, etc

Dana 8th ed.:

26.1.5.1

26 : HYDRATED BORATES CONTAINING HYDROXYL OR HALOGEN
1 : Monoborates

Hey's CIM Ref.:

9.3.25

9 : Borates
3 : Borates of Ca and Sr

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Symbol	Source	Reference
Hen	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 HenmiliteHide

Lustre:

Vitreous

Transparency:

Transparent

Colour:

Blue-violet

Streak:

Very pale violet to nearly white

Hardness:

1½ - 2 on Mohs scale

Comment:

Lower than pentahydroborite

Tenacity:

Fragile

Density:

2.51 g/cm³ (Measured) 2.523 g/cm³ (Calculated)

Optical Data of HenmiliteHide

Type:

Biaxial (-)

RI values:

n_α = 1.585(2) n_β = 1.608 n_γ = 1.615(2)

2V:

Measured: 58° , Calculated: 56°

Max Birefringence:

δ = 0.030

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.

Surface Relief:

Moderate

Dispersion:

small

Pleochroism:

Strong

Comments:

X = pale pink, Y = pale purple, and Z = very pale blue

Comments:

Inclined extinction

Chemistry of HenmiliteHide

Mindat Formula:

Ca₂Cu[B(OH)₄]₂(OH)₄

Elements listed:

B, Ca, Cu, H, O - search for minerals with similar chemistry

Crystallography of HenmiliteHide

Crystal System:

Triclinic

Class (H-M):

1 - Pinacoidal

Space Group:

Cell Parameters:

a = 5.7617(5) Å, b = 7.9774(6) Å, c = 5.6488(4) Å
α = 109.611(6)°, β = 91.473(7)°, γ = 83.686(7)°

Ratio:

a:b:c = 0.722 : 1 : 0.708

Unit Cell V:

243.08 Å³ (Calculated from Unit Cell)

Morphology:

Well developed {100} and {010} pinacoids

Crystal StructureHide

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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)
0001050	Henmilite	Nakai I, Okada H, Masutomi K, Koyama E, Nagashima K (1986) Henmilite, Ca2Cu(OH)4[B(OH)4]2, a new mineral from Fuka, Okayama Prefecture, Japan. II. Crystal structure American Mineralogist 71 1236-1239		1986		0	293

CIF Raw Data - click here to close

data_global
_chemical_name_mineral 'Henmilite'
loop_
_publ_author_name
'Nakai I'
'Okada H'
'Masutomi K'
'Koyama E'
'Nagashima K'
_journal_name_full 'American Mineralogist'
_journal_volume 71 
_journal_year 1986
_journal_page_first 1236
_journal_page_last 1239
_publ_section_title
;
 Henmilite, Ca2Cu(OH)4[B(OH)4]2, a new mineral from Fuka, Okayama Prefecture,
 Japan. II. Crystal structure
;
_database_code_amcsd 0001050
_chemical_formula_sum 'Ca2 Cu B2 O12 H12'
_cell_length_a 5.7617
_cell_length_b 7.9774
_cell_length_c 5.6488
_cell_angle_alpha 109.611
_cell_angle_beta 91.473
_cell_angle_gamma 83.686
_cell_volume 243.076
_exptl_crystal_density_diffrn      2.524
_symmetry_space_group_name_H-M 'P -1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Ca   0.50791   0.24095   0.22595 ?
Cu   0.00000   0.00000   0.00000 ?
B   0.27900   0.40680   0.74800 ?
O1   0.30610  -0.01920   0.14550 ?
O2   0.84040   0.06840   0.32390 ?
O3   0.24670   0.29070   0.89720 ?
O4   0.15230   0.35380   0.51060 ?
O5   0.78790   0.40550   0.09780 ?
O6   0.52610   0.39830   0.67420 ?
H1   0.70500   0.04000   0.73500   0.00633
H2   0.92300   0.06500   0.42700   0.02533
H3   0.22600   0.19400   0.82800   0.04306
H4   0.04300   0.41800   0.52600   0.02533
H5   0.90400   0.38500   0.05800   0.02533
H6   0.61900   0.38700   0.76800   0.01900
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Ca 0.00962 0.00936 0.01071 -0.00082 0.00012 0.00268
Cu 0.00977 0.01035 0.01338 -0.00111 0.00145 0.00340
B 0.00980 0.00961 0.01061 -0.00087 -0.00015 0.00383
O1 0.01113 0.01159 0.01549 -0.00195 0.00062 0.00322
O2 0.01346 0.01668 0.01463 0.00152 0.00154 0.00564
O3 0.01611 0.01075 0.01492 -0.00108 0.00093 0.00665
O4 0.01395 0.01555 0.01291 -0.00217 -0.00417 0.00161
O5 0.01329 0.00820 0.01420 -0.00108 0.00062 0.00181
O6 0.00997 0.01951 0.01176 -0.00130 0.00015 0.00544

X-Ray Powder DiffractionHide

Powder Diffraction Data:

d-spacing	Intensity
5.25 Å	(vs)
4.35 Å	(s)
3.709 Å	(s)
3.302 Å	(s)
2.494 Å	(sb)
2.427 Å	(sb)
2.346 Å	(s)

Geological EnvironmentHide

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 HenmiliteHide

Type Locality:

ⓘ Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan

General Appearance of Type Material:

Anhedral masses and rarely as euhedral crystals up to 0.2 mm growing on the surface of, and within, pentahydroborite.

Place of Conservation of Type Material:

Department of Geology, National Science Museum, Tokyo.

Geological Setting of Type Material:

In pentahydroborite veins at a deposit of marble and contact-metamorphosed limestone / skarn.

Associated Minerals at Type Locality:

Pentahydroborite

Calcite

Brucite

Reference:

Nakai, I., Okada, H., Masutomi, K., Koyama, E. and Nagashima, K. (1986) Henmilite, Ca2Cu(OH)4[B(OH)4]2, a new mineral from Fuka, Okayama Prefecture, Japan. American Mineralogist: 71: 1234-1239.

Download:

https://rruff.info/rruff_1.0/uploads/AM71_1234.pdf

Synonyms of HenmiliteHide

IMA1981-050

Other Language Names for HenmiliteHide

German:Henmilit

Russian:Хенмилит

Spanish:Henmilita

Common AssociatesHide

Associated Minerals Based on Photo Data:

44 photos of Henmilite associated with Olshanskyite	Ca₂[B₃O₃(OH)₆](OH) · 3H₂O
13 photos of Henmilite associated with Calcite	CaCO₃
4 photos of Henmilite associated with Pentahydroborite	CaB₂O(OH)₆ · 2H₂O
3 photos of Henmilite associated with Chiyokoite	Ca₃Si(CO₃)[B(OH)₄]O (OH)₅ · 12H₂O
3 photos of Henmilite associated with Shimazakiite	Ca₂B_2-xO_5-3x(OH)_3x (x = 0~0.06)
1 photo of Henmilite associated with Buryatite	Ca₃(Si,Fe³⁺,Al)(SO₄)B(OH)₄(OH,O)₆ · 12H₂O
1 photo of Henmilite associated with Charlesite	Ca₆(Al,Si)₂(SO₄)₂[B(OH)₄](OH,O)₁₂ · 26H₂O

Related Minerals - Strunz-mindat Grouping Hide

6.AC.05	Sinhalite	MgAl(BO₄)	Orth. mmm (2/m 2/m 2/m)
6.AC.10	Pseudosinhalite	Mg₂Al₃(BO₃)₂(OH)O₃	Mon. 2/m : P2₁/b
6.AC.15	Béhierite	(Ta⁵⁺,Nb⁵⁺)(BO₄)	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
6.AC.15	Schiavinatoite	(Nb,Ta)(BO₄)	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
6.AC.20	Frolovite	Ca[B(OH)₄]₂	Tric. 1 : P1
6.AC.25	Hexahydroborite	Ca[B(OH)₄]₂ · 2H₂O or CaB₂O₄ · 6H₂O	Mon. 2/m : B2/b
6.AC.35	Bandylite	Cu[B(OH)₄]Cl	Tet. 4/mmm (4/m 2/m 2/m) : P4/nmm
6.AC.40	Teepleite	Na₂[B(OH)₄]Cl	Tet. 4/mmm (4/m 2/m 2/m) : P4/nmm
6.AC.45	Moydite-(Y)	Y[B(OH)₄](CO₃)	Orth. mmm (2/m 2/m 2/m) : Pbca
6.AC.50	Carboborite	Ca₂Mg[B(OH)₄]₂(CO₃)₂ · 4H₂O	Mon. 2/m
6.AC.55	Sulfoborite	Mg₃[B(OH)₄]₂(SO₄)(OH,F)₂	Orth. mmm (2/m 2/m 2/m) : Pnma
6.AC.60	Lüneburgite	Mg₃[B₂(OH)₆](PO₄)₂ · 6H₂O	Tric. 1 : P1
6.AC.65	Seamanite	Mn²⁺₃[B(OH)₄](PO₄)(OH)₂	Orth. mmm (2/m 2/m 2/m)
6.AC.70	Cahnite	Ca₂[B(OH)₄](AsO₄)	Tet. 4 : P4

Other InformationHide

Notes:

Easily soluble in (1:2) HCl and (1:2) HNO3

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 HenmiliteHide

mindat.org URL:

https://www.mindat.org/min-1866.html
Please feel free to link to this page.

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External Links:

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Raman and XRD data at RRUFF project

References and PDF downloads at RRUFF project

American Mineralogist Crystal Structure Database

Handbook of Mineralogy page PDF

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References for HenmiliteHide

Reference List:

Kusachi, I. (1992) New data on mineralogical properties of henmilite. Kobutsugaku Zasshi: 21(3): 127-130.

Grew, Edward S., Anovitz, Lawrence M., Grew, Edward S., Anovitz, Lawrence M. - Eds. (1996) Boron - Mineralogy, Petrology and Geochemistry. Reviews in Mineralogy Vol. 33. Mineralogical Society of America

Frost, Ray L., Xi, Yunfei (2013) Vibrational spectroscopy of the borate mineral henmilite Ca₂Cu[B(OH)₄]₂(OH)₄. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 103. 356-360 doi:10.1016/j.saa.2012.11.009

Petrov, Alfredo (2016) Henmilite: The Dark Blue Borate from the Fuka Mine, Japan. Rocks & Minerals, 91 (1) 54-58 doi:10.1080/00357529.2016.1099134

(2023) Henmilite. Handbook of Mineralogy. Mineralogical Society of America

Localities for HenmiliteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the

symbol to view information about a locality. The

symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- 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). ~~Struck out~~ - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.

Japan (TL)

Okayama Prefecture

Takahashi City

Bitchū

Fuka

ⓘ Fuka mine (TL)

Nakai et al. (1986) +2 other references

Henmilite

About HenmiliteHide

Unique IdentifiersHide

IMA Classification of HenmiliteHide

Classification of HenmiliteHide

Mineral SymbolsHide

Physical Properties of HenmiliteHide

Optical Data of HenmiliteHide

Chemistry of HenmiliteHide

Crystallography of HenmiliteHide

Crystal StructureHide

X-Ray Powder DiffractionHide

Geological EnvironmentHide

Type Occurrence of HenmiliteHide

Synonyms of HenmiliteHide

Other Language Names for HenmiliteHide

Common AssociatesHide

Related Minerals - Strunz-mindat GroupingHide

Other InformationHide

Internet Links for HenmiliteHide

References for HenmiliteHide

Localities for HenmiliteHide

Locality ListHide

Related Minerals - Strunz-mindat Grouping Hide