Danburite
A valid IMA mineral species - grandfathered
This page kindly sponsored by Danbury Mineralogical Society
About Danburite
Formula:
CaB2Si2O8
Colour:
Pale yellow, yellowish-brown, colourless
Lustre:
Vitreous, Greasy
Hardness:
7 - 7½
Specific Gravity:
2.93 - 3.02
Crystal System:
Orthorhombic
Name:
For the type locality at Danbury, Connecticut, USA.
Type Locality:
The calcium analogue of Maleevite and Pekovite.
The paracelsian topology might invoke alternatively grouping - "paracelsian group" - also comprising danburite, pekovite, maleevite, hurlbutite and strontiohurlbutite.
The paracelsian topology might invoke alternatively grouping - "paracelsian group" - also comprising danburite, pekovite, maleevite, hurlbutite and strontiohurlbutite.
Visit gemdat.org for gemological information about Danburite.
Unique Identifiers
Mindat ID:
1218
Long-form identifier:
mindat:1:1:1218:4
GUID
(UUID V4):
(UUID V4):
bd7009b2-2cac-4465-aaf1-ae08ccb866ac
IMA Classification of Danburite
Approved, 'Grandfathered' (first described prior to 1959)
First published:
1839
Classification of Danburite
9.FA.65
9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H2O
A : Tektosilicates without additional non-tetrahedral anions
9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H2O
A : Tektosilicates without additional non-tetrahedral anions
56.3.1.1
56 : SOROSILICATES Si2O7 Groups, With Additional O, OH, F and H2O
3 : Si2O7 Groups and O, OH, F, and H2O with[Si2O7] with borate groups
56 : SOROSILICATES Si2O7 Groups, With Additional O, OH, F and H2O
3 : Si2O7 Groups and O, OH, F, and H2O with[Si2O7] with borate groups
17.5.11
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.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Symbol | Source | Reference |
---|---|---|
Dbu | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Dbr | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Danburite
Vitreous, Greasy
Transparency:
Transparent, Translucent
Colour:
Pale yellow, yellowish-brown, colourless
Streak:
White
Hardness:
7 - 7½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
Indistinct on {001}
Indistinct on {001}
Fracture:
Irregular/Uneven, Sub-Conchoidal
Density:
2.93 - 3.02 g/cm3 (Measured) 2.99 g/cm3 (Calculated)
Optical Data of Danburite
Type:
Biaxial (+/-)
RI values:
nα = 1.627 - 1.633 nβ = 1.630 - 1.636 nγ = 1.633 - 1.639
2V:
Measured: 88° to 90°, Calculated: 88°
Max Birefringence:
δ = 0.006
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
Dispersion:
r < v strong
Chemistry of Danburite
Mindat Formula:
CaB2Si2O8
Elements listed:
Common Impurities:
Fe,Mn,Al,Mg,Sr,Na
Crystallography of Danburite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Cell Parameters:
a = 8.038(3) Å, b = 8.752(5) Å, c = 7.730 Å
Ratio:
a:b:c = 0.918 : 1 : 0.883
Unit Cell V:
543.79 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Prismatic crystals, disseminated masses.
Comment:
Space Group: Pnam:
Crystallographic forms of Danburite
Crystal Atlas:
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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) |
---|---|---|---|---|---|---|---|
0000395 | Danburite | Phillips M W, Gibbs G V, Ribbe P H (1974) The crystal structure of danburite: A comparison with anorthite, albite, and reedmergnerite American Mineralogist 59 79-85 | 1974 | 0 | 293 | ||
0017950 | Danburite | Dunbar C, Machatschki F (1931) The structure of danburite, CaB2Si2O8 _cod_database_code 1011048 Zeitschrift fur Kristallographie 76 133-145 | 1931 | 0 | 293 | ||
0010946 | Danburite | Sugiyama K, Takeuchi Y (1985) Unusual thermal expansion of a B-O bond in the structure of danburite CaB2Si2O8 Zeitschrift fur Kristallographie 173 293-304 | 1985 | Toroku mine, Miyazaki Prefecture, Japan | 0 | 293 | |
0010947 | Danburite | Sugiyama K, Takeuchi Y (1985) Unusual thermal expansion of a B-O-bond in the structure of danburite CaB2Si2O8 Zeitschrift fur Kristallographie 173 293-304 | 1985 | Toroku mine, Miyazaki Prefecture, Japan | 0 | 293 | |
0010948 | Danburite | Sugiyama K, Takeuchi Y (1985) Unusual thermal expansion of a B-O-bond in the structure of danburite CaB2Si2O8 Zeitschrift fur Kristallographie 173 293-304 | 1985 | Toroku mine, Miyazaki Prefecture, Japan | 0 | 293 | |
0010949 | Danburite | Sugiyama K, Takeuchi Y (1985) Unusual thermal expansion of a B-O-bond in the structure of danburite CaB2Si2O8 Zeitschrift fur Kristallographie 173 293-304 | 1985 | Toroku mine, Miyazaki Prefecture, Japan | 0 | 293 | |
0010950 | Danburite | Sugiyama K, Takeuchi Y (1985) Unusual thermal expansion of a B-O-bond in the structure of danburite CaB2Si2O8 Zeitschrift fur Kristallographie 173 293-304 | 1985 | Toroku mine, Miyazaki Prefecture, Japan | 0 | 293 | |
0010951 | Danburite | Sugiyama K, Takeuchi Y (1985) Unusual thermal expansion of a B-O-bond in the structure of danburite CaB2Si2O8 Zeitschrift fur Kristallographie 173 293-304 | 1985 | Toroku mine, Miyazaki Prefecture, Japan | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
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Radiation - Copper Kα
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
3.57 Å | (100) |
2.961 Å | (80) |
2.743 Å | (65) |
2.655 Å | (55) |
2.729 Å | (40) |
1.435 Å | (40) |
3.65 Å | (35) |
Comments:
Maglovec Hill, Presov, Slovakia
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4a: Earth’s earliest continental crust | >4.4-3.0 |
19 : Granitic intrusive rocks | |
Near-surface Processes | |
25 : Evaporites (prebiotic) | |
High-𝑇 alteration and/or metamorphism | |
31 : Thermally altered carbonate, phosphate, and iron formations | |
32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
Stage 5: Initiation of plate tectonics | <3.5-2.5 |
40 : Regional metamorphism (greenschist, amphibolite, granulite facies) |
Geological Setting:
Granite and metamorphosed carbonates, evaporites.
Type Occurrence of Danburite
General Appearance of Type Material:
Scattered crystals in feldspar, up to 2.5 cm in size.
Place of Conservation of Type Material:
No designated type material.
Associated Minerals at Type Locality:
Reference:
Shepard, C.U. (1839) Notice of danburite, a new mineral species. American Journal of Science and Arts: 35: 137-139.
Synonyms of Danburite
Other Language Names for Danburite
Common Associates
Associated Minerals Based on Photo Data:
156 photos of Danburite associated with Calcite | CaCO3 |
93 photos of Danburite associated with Quartz | SiO2 |
43 photos of Danburite associated with Pyrite | FeS2 |
40 photos of Danburite associated with Datolite | CaB(SiO4)(OH) |
35 photos of Danburite associated with Magnesio-riebeckite | ◻{Na2}{Mg3Fe3+2}(Si8O22)(OH)2 |
31 photos of Danburite associated with Citrine | SiO2 |
17 photos of Danburite associated with Amethyst | SiO2 |
17 photos of Danburite associated with Tourmaline | AD3G6 (T6O18)(BO3)3X3Z |
17 photos of Danburite associated with Sphalerite | ZnS |
17 photos of Danburite associated with Chalcopyrite | CuFeS2 |
Related Minerals - Strunz-mindat Grouping
9.FA. | Hexacelsian | BaAl2Si2O8 |
9.FA. | Wodegongjieite | KCa3(Al7Si9)O32 |
9.FA.05 | Kaliophilite | KAlSiO4 |
9.FA.05 | Kalsilite | KAlSiO4 |
9.FA.05 | Nepheline | Na3K(Al4Si4O16) |
9.FA.05 | Panunzite | (K,Na)AlSiO4 |
9.FA.05 | Trikalsilite | K2NaAl3(SiO4)3 |
9.FA.05 | Yoshiokaite | (Ca,Na)[Al(Al,Si)O4] |
9.FA.05 | Carnegieite | NaAlSiO4 |
9.FA.05 va | Germanate-nepheline | (Na,K)AlGeO4 |
9.FA.05 | Megakalsilite | KAlSiO4 |
9.FA.05 | Trinepheline | NaAlSiO4 |
9.FA.05 | Davidsmithite | (Ca,◻)2Na6Al8Si8O32 |
9.FA.10 | Malinkoite | NaBSiO4 |
9.FA.15 | Virgilite | LiAlSi2O6 |
9.FA.25 | Lisitsynite | KBSi2O6 |
9.FA.30 | Buddingtonite | (NH4)(AlSi3O8) |
9.FA.30 | Celsian | Ba(Al2Si2O8) |
9.FA.30 | Microcline | K(AlSi3O8) |
9.FA.30 | Orthoclase | K(AlSi3O8) |
9.FA.30 | Sanidine | K(AlSi3O8) |
9.FA.30 | Rubicline | Rb(AlSi3O8) |
9.FA.30 va | Germanate-celsian | BaAl2Ge2O8 |
9.FA.30 | Monalbite | NaAlSi3O8 |
9.FA.30 | Ferrisanidine | K[Fe3+Si3O8] |
9.FA.35 | Albite | Na(AlSi3O8) |
9.FA.35 | Anorthite | Ca(Al2Si2O8) |
9.FA.35 | Reedmergnerite | NaBSi3O8 |
9.FA.40 | Paracelsian | Ba(Al2Si2O8) |
9.FA.45 | Svyatoslavite | Ca(Al2Si2O8) |
9.FA.45 | Kumdykolite | Na(AlSi3O8) |
9.FA.50 | Slawsonite | Sr(Al2Si2O8) |
9.FA.55 | Lisetite | CaNa2Al4Si4O16 |
9.FA.60 | Banalsite | Na2BaAl4Si4O16 |
9.FA.60 | Stronalsite | Na2SrAl4Si4O16 |
9.FA.65 | Maleevite | BaB2Si2O8 |
9.FA.65 | Pekovite | SrB2Si2O8 |
9.FA.70 | Stöfflerite | CaAl2Si2O8 |
9.FA.70 | Lingunite | (Na,Ca)AlSi3O8 |
9.FA.70 | Liebermannite | KAlSi3O8 |
9.FA.75 | Kokchetavite | K(AlSi3O8) |
Other Information
Thermal Behaviour:
Heated alone, before the blowpipe, it phosphoresces and fuses slowly, without swelling, into a white blebby, transparent glass (fusability scale 3.5), coloring the flame green due to boron. On cooling the glass becomes milky-white. With borax, it melts with effervescence into a transparent globule.
In a closed tube, it gives off some moisture, and phosphoresces brilliantly with a reddish yellow light.
In a closed tube, it gives off some moisture, and phosphoresces brilliantly with a reddish yellow light.
Notes:
Slightly soluble in HCl, sufficiently so to give the reaction for boric acid with turmeric paper. Powdered danburite is slowly soluble.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Danburite in petrology
An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.
Internet Links for Danburite
mindat.org URL:
https://www.mindat.org/min-1218.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Danburite
Localities for Danburite
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.
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Toroku Mine, Takachiho, Nishiusuki District, Miyazaki Prefecture, Japan