Harkerite
A valid IMA mineral species - grandfathered
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About Harkerite
Formula:
Ca48Mg16[AlSi4O15(OH)]4(BO3)16(CO3)16 · 2(H2O,HCl)
Formerly given as Ca12Mg4Al(BO3)3(SiO4)4(CO3)5 · H2O
Evans et al. (2018) report the formula as ~Ca48Mg16[AlSi4(O,OH)16]4(BO3)16(CO3)16(HCl,H2O)2
Finally redefined to the formula given above.
Evans et al. (2018) report the formula as ~Ca48Mg16[AlSi4(O,OH)16]4(BO3)16(CO3)16(HCl,H2O)2
Finally redefined to the formula given above.
Colour:
White; also tannish brown
Lustre:
Sub-Vitreous, Waxy, Dull
Specific Gravity:
2.96
Crystal System:
Trigonal
Name:
Named in 1948 by Cecil Edgar Tilley for systematic petrologist Alfred Harker (19 February 1859, Hull, Yorkshire, UK - 28 July 1939) of the Scottish Geological Survey.
White to tannish brown pseudo-octahedral crystals.
Structurally related to sakhaite with which it forms a solid solution (Sakhaite-Harkerite solid solution).
Compare UM1990-59-SiO:AlBCHMg.
Seems to be (in particular) a hydrochloride (chlorhydrate).
Structurally related to sakhaite with which it forms a solid solution (Sakhaite-Harkerite solid solution).
Compare UM1990-59-SiO:AlBCHMg.
Seems to be (in particular) a hydrochloride (chlorhydrate).
Unique Identifiers
Mindat ID:
1819
Long-form identifier:
mindat:1:1:1819:3
GUID
(UUID V4):
(UUID V4):
b9c7dac8-5d0d-47b6-804b-6203c6e26d33
IMA Classification of Harkerite
Approved, 'Grandfathered' (first described prior to 1959)
IMA status notes:
Redefined by the IMA
First published:
1951
Approval history:
Final redefinitions due to data from the Newsletter #60 (Miyawaki et al. 2021).
Classification of Harkerite
6.AB.70
6 : BORATES
A : Monoborates
B : BO3, with additional anions; 1(D) + OH, etc.
6 : BORATES
A : Monoborates
B : BO3, with additional anions; 1(D) + OH, etc.
17.1.9.1
17 : COMPOUND CARBONATES
1 : Miscellaneous
17 : COMPOUND CARBONATES
1 : Miscellaneous
17.5.16
17 : Silicates Containing other Anions
5 : Borosilicates
17 : Silicates Containing other Anions
5 : Borosilicates
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 |
---|---|---|
Hkr | 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 Harkerite
Sub-Vitreous, Waxy, Dull
Transparency:
Translucent
Colour:
White; also tannish brown
Streak:
White
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
2.96 g/cm3 (Measured) 3.00 g/cm3 (Calculated)
Optical Data of Harkerite
Type:
Uniaxial
RI values:
nα = 1.649 - 1.653 nβ = 1.649 - 1.653
Max Birefringence:
δ = 1.649
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:
Moderate
Optical Extinction:
May be anomalously biaxial
Pleochroism:
Non-pleochroic
Chemistry of Harkerite
Mindat Formula:
Ca48Mg16[AlSi4O15(OH)]4(BO3)16(CO3)16 · 2(H2O,HCl)
Formerly given as Ca12Mg4Al(BO3)3(SiO4)4(CO3)5 · H2O
Evans et al. (2018) report the formula as ~Ca48Mg16[AlSi4(O,OH)16]4(BO3)16(CO3)16(HCl,H2O)2
Finally redefined to the formula given above.
Formerly given as Ca12Mg4Al(BO3)3(SiO4)4(CO3)5 · H2O
Evans et al. (2018) report the formula as ~Ca48Mg16[AlSi4(O,OH)16]4(BO3)16(CO3)16(HCl,H2O)2
Finally redefined to the formula given above.
Common Impurities:
TR,Ce,Fe,Mn,Sr,F,Cl
Crystallography of Harkerite
Crystal System:
Trigonal
Class (H-M):
3m (3 2/m) - Hexagonal Scalenohedral
Space Group:
R3m
Cell Parameters:
a = 18.131 Å
α = 33.46°
α = 33.46°
Unit Cell V:
1,613.62 ų (Calculated from Unit Cell)
Morphology:
Pseudo-octahedrons.
Comment:
Pseudo-isometric Fd3m. Hexagonal cell-parameters: a = 10.439, c = 51.303 Å (Z =3).
Crystal Structure
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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) |
---|---|---|---|---|---|---|---|
0000564 | Harkerite | Giuseppetti G, Mazzi F, Tadini C (1977) The crystal structure of harkerite American Mineralogist 62 263-272 | 1977 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
5.22 Å | (70) |
3.39 Å | (60) |
3.01 Å | (60) |
2.84 Å | (60) |
2.61 Å | (100) |
2.13 Å | (80) |
1.84 Å | (90) |
1.51 Å | (70) |
Comments:
10-0465
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
High-𝑇 alteration and/or metamorphism | |
31 : Thermally altered carbonate, phosphate, and iron formations |
Geological Setting:
High temperature contact metamorphism assemblages.
Type Occurrence of Harkerite
General Appearance of Type Material:
Simple pseudo-octahedrons. Sometimes altered to calcite.
Place of Conservation of Type Material:
n.d.
Geological Setting of Type Material:
Skarn.
Associated Minerals at Type Locality:
Reference:
Tilley, C.E. (1951) The zoned contact-skarns of the Broadford area, Skye: a study of boron-fluorine metasomatism in dolomites. Mineralogical Magazine: 29: 621-666.
Other Language Names for Harkerite
Relationship of Harkerite to other Species
Forms a series with:
Common Associates
Associated Minerals Based on Photo Data:
10 photos of Harkerite associated with Calcite | CaCO3 |
6 photos of Harkerite associated with Monticellite | CaMgSiO4 |
5 photos of Harkerite associated with Phlogopite | KMg3(AlSi3O10)(OH)2 |
3 photos of Harkerite associated with Magnetite | Fe2+Fe3+2O4 |
3 photos of Harkerite associated with Vesuvianite | Ca19Fe3+Al4(Al6Mg2)(◻4)◻[Si2O7]4[(SiO4)10]O(OH)9 |
3 photos of Harkerite associated with Cuspidine | Ca8(Si2O7)2F4 |
2 photos of Harkerite associated with Malachite | Cu2(CO3)(OH)2 |
2 photos of Harkerite associated with Hydromagnesite | Mg5(CO3)4(OH)2 · 4H2O |
1 photo of Harkerite associated with Löllingite | FeAs2 |
1 photo of Harkerite associated with Riversideite | Ca5(HSi3O9)2 · 2H2O |
Related Minerals - Strunz-mindat Grouping
6.AB. | Rhabdoborite-(Mo) | Mg12Mo6+1.33O6(BO3)6F2 |
6.AB. | Chubarovite | KZn2(BO3)Cl2 |
6.AB. | Savelievaite | Mg2Cr3+O2(BO3) |
6.AB.05 | Hambergite | Be2(BO3)(OH) |
6.AB.10 | Berborite | Be2(BO3)(OH,F) · H2O |
6.AB.15 | Jeremejevite | Al6(BO3)5(F,OH)3 |
6.AB.20 | Warwickite | (Mg,Ti,Fe,Al)2O(BO3) |
6.AB.20 | Yuanfuliite | Mg(Fe3+,Al)O(BO3) |
6.AB.25 | Karlite | (Mg,Al)6.5(BO3)3(OH)4(◻,Cl)0.5 |
6.AB.30 | Azoproite | (Mg,Fe2+)2(Fe3+,Ti,Mg)(BO3)O2 |
6.AB.30 | Bonaccordite | Ni2Fe3+(BO3)O2 |
6.AB.30 | Fredrikssonite | Mg2(Mn3+,Fe3+)(BO3)O2 |
6.AB.30 | Ludwigite | Mg2Fe3+(BO3)O2 |
6.AB.30 | Vonsenite | Fe2+2Fe3+(BO3)O2 |
6.AB.30 | Marinaite | Cu2Fe3+O2(BO3) |
6.AB.35 | Pinakiolite | (Mg,Mn2+)2Mn3+(BO3)O2 |
6.AB.35 | Folvikite | Sb5+Mn3+(Mg,Mn2+)10O8(BO3)4 |
6.AB.40 | Blatterite | Sb5+3(Mn3+,Fe3+)9(Mn2+,Mg)35(BO3)16O32 |
6.AB.40 | Chestermanite | Mg2(Fe3+,Mn3+,Al,Sb3+)(BO3)O2 |
6.AB.40 | Orthopinakiolite | (Mg,Mn2+)2Mn3+(BO3)O2 |
6.AB.40 | Takéuchiite | (Mg,Mn2+)2(Mn3+,Fe3+)(BO3)O2 |
6.AB.45 | Hulsite | (Fe2+,Mg)2(Fe3+,Sn)(BO3)O2 |
6.AB.45 | Magnesiohulsite | (Mg,Fe2+)2(Fe3+,Sn,Mg)(BO3)O2 |
6.AB.45 | Aluminomagnesiohulsite | (Mg,Fe2+)2(Al,Mg,Sn)(BO3)O2 |
6.AB.50 | Fluoborite | Mg3(BO3)(F,OH)3 |
6.AB.50 | Hydroxylborite | Mg3(BO3)(OH)3 |
6.AB.55 | Shabynite | Mg5(BO3)(OH)5(Cl,OH)2 · 4H2O |
6.AB.55 | Wightmanite | Mg5(BO3)O(OH)5 · 2H2O |
6.AB.60 | Gaudefroyite | Ca4Mn3+2-3(BO3)3(CO3)(O,OH)3 |
6.AB.65 | Sakhaite | Ca48Mg16(BO3)32(CO3)16 · 2(H2O,HCl) |
6.AB.75 | Pertsevite-(F) | Mg2(BO3)(F,OH) |
6.AB.75 | Pertsevite-(OH) | Mg2(BO3)(OH) |
6.AB.80 | Jacquesdietrichite | Cu2(H2BO3)(OH)3 |
6.AB.85 | Painite | CaZrAl9(BO3)O15 |
6.AB.85 | Rhabdoborite-(V) | Mg12(V5+,Mo6+,W6+)1.5O6{[BO3]6-x[(P,As)O4]xF2-x} (x < 1) |
6.AB.85 | Rhabdoborite-(W) | Mg12(W6+,V5+)1.5O6{[BO3]6-x[(P,As)O4]xF2-x} |
6.AB.90 | Mengxianminite | (Ca,Na)2Sn2(Mg,Fe)3Al8[(BO3)(BeO4)O6]2 |
Fluorescence of Harkerite
Red fluorescence in shortwave UV.
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 Harkerite
mindat.org URL:
https://www.mindat.org/min-1819.html
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References for Harkerite
Reference List:
Giuseppetti, Giuseppe, Mazzi, Fiorenzo, Tadini, Carla (1977) The crystal structure of harkerite. American Mineralogist, 62 (3-4) 263-272
Localities for Harkerite
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).
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.
All localities listed without proper references should be considered as questionable.
China | |
| Wang (1983) +1 other reference |
Italy | |
| Barbieri et al. (1973) +1 other reference |
Christof Schäfer collection | |
| fluid inclusions and mineral chemistry. American Mineralogist (7-8) +2 other references |
Kazakhstan | |
| Pekov (1998) |
Namibia | |
| Dunn (1991) |
Russia | |
| Koneva et al. (1991) |
| Aleksandrov (1998) |
Sweden | |
| Holtstam et al. (1995) |
UK | |
| |
| Tilley (1951) |
USA | |
| ... +1 other reference |
| Contrib. Mineral. Petrol. 74 (1980) +1 other reference |
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Kombat Mine, Kombat, Otavi Constituency, Otjozondjupa Region, Namibia