Brookite
A valid IMA mineral species - grandfathered
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About Brookite
Formula:
TiO2
Colour:
Brown, yellowish brown, reddish brown; dark brown to iron-black; yellowish brown to dark brown in transmitted light
Lustre:
Adamantine, Sub-Adamantine, Vitreous, Sub-Vitreous, Sub-Metallic
Hardness:
5½ - 6
Specific Gravity:
4.08 - 4.18
Crystal System:
Orthorhombic
Name:
Named in 1825 by Serve-Dieu Abailard "Armand" Lévy in honor of Henry James Brooke [May 25, 1771 Exeter, England, UK - 1857 London, England, UK], wealthy textile manufacturer and actuary, amateur English crystallographer and mineralogist. Brooke discovered 12 minerals: Annabergite, Autunite, Arfvedsonite, Caledonite, Childrenite, Linarite, Nitronatrite, Susannite, Thomsonite, and Whewellite. He was author of A Familiar Introduction to Crystallography and co-author of Elementary Introduction to Mineralogy (1852). He wrote numerous scientific articles and was a fellow of the Royal Society, Geological Society of London, and the Linnaen Society.
Polymorph of:
Brookite is one of the five forms of titanium dioxide found in nature.
Visit gemdat.org for gemological information about Brookite.
Visit gemdat.org for gemological information about Brookite.Unique Identifiers
Mindat ID:
787
Long-form identifier:
mindat:1:1:787:8
Similar Names
| Bhreckite | ||
| Borickite | A synonym of 'Bořickýite' | |
| Braggite | A valid IMA mineral species | PdPt3S4 |
| Brockite | A valid IMA mineral species | (Ca,Th,Ce)PO4 · H2O |
| Broggite | A variety of 'Bitumen' ['Petroleum'] |
IMA Classification of Brookite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ti4+O2
Type description reference:
Classification of Brookite
4.DD.10
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
D : With medium-sized cations; frameworks of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
D : With medium-sized cations; frameworks of edge-sharing octahedra
4.4.5.1
4 : SIMPLE OXIDES
4 : AX2
4 : SIMPLE OXIDES
4 : AX2
7.9.4
7 : Oxides and Hydroxides
9 : Oxides of Ti
7 : Oxides and Hydroxides
9 : Oxides of Ti
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 for Standard |
|---|---|---|
| Brk | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Brk | Kretz (1983) | Kretz, R. (1983) Symbols of rock-forming minerals. American Mineralogist, 68, 277–279. |
| Brk | Siivolam & Schmid (2007) | Siivolam, J. and Schmid, R. (2007) Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Web-version 01.02.07. IUGS Commission on the Systematics in Petrology. download |
| Brk | Whitney & Evans (2010) | Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187 doi:10.2138/am.2010.3371 |
| Brk | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Pronunciation of Brookite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Brookite
Adamantine, Sub-Adamantine, Vitreous, Sub-Vitreous, Sub-Metallic
Transparency:
Transparent, Translucent, Opaque
Colour:
Brown, yellowish brown, reddish brown; dark brown to iron-black; yellowish brown to dark brown in transmitted light
Streak:
White to greyish white or yellowish white
Hardness:
5½ - 6 on Mohs scale
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
on {120}, in traces on {001}
on {120}, in traces on {001}
Fracture:
Irregular/Uneven, Sub-Conchoidal
Density:
4.08 - 4.18 g/cm3 (Measured) 4.133 g/cm3 (Calculated)
Optical Data of Brookite
Type:
Biaxial (+)
RI values:
nα = 2.5831 nβ = 2.5843 nγ = 2.7004
2V:
Calculated: 12° to 20°
Birefringence:
0.1173
Max. Birefringence:
δ = 0.117
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:
Very 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.
Dispersion:
r > v, very strong, with crossed axial dispersion
Optical Extinction:
Parallel
Pleochroism:
Weak
Comments:
Yellow, red, orange to brown
Chemistry of Brookite
Mindat Formula:
TiO2
Elements listed:
Common Impurities:
Fe,Ta,Nb
Crystallography of Brookite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Cell Parameters:
a = 5.4558 Å, b = 9.1819 Å, c = 5.1429 Å
Ratio:
a:b:c = 0.594 : 1 : 0.56
Unit Cell V:
257.63 ų (Calculated from Unit Cell)
Z:
8
Morphology:
Crystals typically tabular on {010}, striated parallel to [001] and elongated; pyramidal {111} or pseudohexagonal with {120} and {111} equally developed; also prismatic on [001] with {120} prominent; rarely tabular on {001} or pseudo-pyramidal.
Twinning:
On {120}, uncertain
Comment:
Space Group: Pcab
Crystallographic forms of Brookite
Crystal Atlas:
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Brookite no.1 - {010} - Goldschmidt (1913-1926)
Brookite no.45 - {120} - Goldschmidt (1913-1926)
Brookite no.78 - {140} - Goldschmidt (1913-1926)
Brookite no.86 - {111} - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by
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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) |
|---|---|---|---|---|---|---|---|
| 0005163 | Brookite | Meagher E P, Lager G A (1979) Polyhedral thermal expansion in the TiO2 polymorphs: Refinement of the crystal structures of rutile and brookite at high temperatures Sample at 625 degrees C The Canadian Mineralogist 17 77-85 |  | 1979 | 0 | 293 | |
| 0005162 | Brookite | Meagher E P, Lager G A (1979) Polyhedral thermal expansion in the TiO2 polymorphs: Refinement of the crystal structures of rutile and brookite at high temperature Sample at 425 degrees C The Canadian Mineralogist 17 77-85 | | 1979 | 0 | 293 | |
| 0005161 | Brookite | Meagher E P, Lager G A (1979) Polyhedral thermal expansion in the TiO2 polymorphs: Refinement of the crystal structures of rutile and brookite at high temperature Sample at 280 degrees C The Canadian Mineralogist 17 77-85 | | 1979 | 0 | 293 | |
| 0005160 | Brookite | Meagher E P, Lager G A (1979) Polyhedral thermal expansion in the TiO2 polymorphs: Refinement of the crystal structures of rutile and brookite at high temperature Sample at 25 degrees C The Canadian Mineralogist 17 77-85 | | 1979 | 0 | 293 | |
| 0011766 | Brookite | Wyckoff R W G (1963) Second edition. Interscience Publishers, New York, New York Crystal Structures 1 239-444 | 1963 | 0 | 293 |
CIF Raw Data - click here to close
Epitaxial Relationships of Brookite
Epitaxial Minerals:
| 'Rutile' | TiO2 |
Epitaxy Comments:
Rutile {110} [001] parallel to brookite {120} [001].
Rutile {110} [001] parallel to brookite {111} [001].
Rutile {110} [001] parallel to brookite {111} [001].
X-Ray Powder Diffraction
Loading XRD data...
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.51 Å | (100) |
| 3.47 Å | (80) |
| 2.90 Å | (90) |
| 2.729 Å | (4) |
| 2.476 Å | (25) |
| 2.409 Å | (18) |
| 2.370 Å | (6) |
| 2.344 Å | (4) |
| 2.332 Å | (4) |
| 2.296 Å | (5) |
| 2.254 Å | (8) |
| 2.244 Å | (18) |
| 2.133 Å | (16) |
| 1.969 Å | (16) |
| 1.893 Å | (30) |
| 1.851 Å | (18) |
| 1.833 Å | (3) |
| 1.757 Å | (3) |
| 1.691 Å | (20) |
| 1.662 Å | (30) |
| 1.649 Å | (5) |
| 1.610 Å | (13) |
| 1.597 Å | (2) |
| 1.541 Å | (7) |
| 1.494 Å | (10) |
| 1.473 Å | (4) |
| 1.466 Å | (9) |
| 1.461 Å | (12) |
| 1.452 Å | (12) |
| 1.442 Å | (6) |
| 1.434 Å | (10) |
| 1.417 Å | (9) |
| 1.364 Å | (5) |
| 1.336 Å | (8) |
| 1.319 Å | (3) |
| 1.312 Å | (2) |
| 1.285 Å | (2) |
| 1.238 Å | (10) |
| 1.211 Å | (2) |
Comments:
ICDD 29-1360. Recorded on material from Magnet Cove, Arkansas, USA.
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 | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) | |
| 24 : Authigenic minerals in terrestrial sediments (see also #17) | |
| 26 : Hadean detrital minerals | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| 36 : Carbonatites, kimberlites, and related igneous rocks |
Geological Setting:
An accessory mineral in alpine veins in gneiss and schist; in contact metamorphic zones and hydrothermal veinlets; a common detrital mineral.
Type Occurrence of Brookite
General Appearance of Type Material:
Bladed red to brown transparent to translucent bladed crystals with longitudinal striations.
Geological Setting of Type Material:
Hydrothermal vein
Associated Minerals at Type Locality:
Synonyms of Brookite
Other Language Names for Brookite
Varieties of Brookite
| Arkansite | Name for a morphological variety of brookite from Arkansas, USA. Apparently Fe- and Nb-bearing. |
| Niobium-bearing Brookite | Compare also arkansite. |
Common Associates
Associations Based on Photo Data:
| 901 photos of Brookite associated with Quartz | SiO2 |
| 298 photos of Brookite associated with Anatase | TiO2 |
| 184 photos of Brookite associated with Rutile | TiO2 |
| 79 photos of Brookite associated with Albite | Na(AlSi3O8) |
| 38 photos of Brookite associated with Pyrite | FeS2 |
| 38 photos of Brookite associated with Chlorite Group | |
| 28 photos of Brookite associated with 'Smoky Quartz' | SiO2 |
| 21 photos of Brookite associated with Calcite | CaCO3 |
| 16 photos of Brookite associated with Clinochlore | Mg5Al(AlSi3O10)(OH)8 |
| 14 photos of Brookite associated with 'Rock Crystal' | SiO2 |
Related Minerals - Strunz-mindat Grouping
| 4.DD.05 | Anatase | TiO2 |
Fluorescence of Brookite
Not fluorescent in ultraviolet
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 Brookite
mindat.org URL:
https://www.mindat.org/min-787.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Brookite
Reference List:
Zepharovich, V. von (1884) Ueber Brookit, Wulfenit und Skolezit. Zeitschrift für Krystallographie, Mineralogie und Petrographie, 8 (1-6). 577-592 doi:10.1524/zkri.1884.8.1.577
Pauling, Linus; Sturdivant, J. H. (1928) The crystal structure of brookite. Zeitschrift für Kristallographie, 68 (1-6). p.239-256. doi:10.1524/zkri.1928.68.1.239
Sehröder, Alfred (1928) Beiträge zur Kenntnis des Feinbaues des Brookits und des physikalischen Verhaltens sowie derZustandsänderungen der drei natürlichen Titandioxyde. Zeitschrift für Kristallographie, 67 (1-6). 485-542 doi:10.1524/zkri.1928.67.1.485
Arnold, W. (1929) Beiträge zur Kenntnis des Brookit in morphologischer und optischer Hinsicht. Zeitschrift für Kristallographie, 71 (1-6). p.344-405. doi:10.1524/zkri.1929.71.1.344
Holzgang, F. (1930) Zur Morphologie von Fluorit, Scheelit und Brookit. Schweizerische Mineralogische und Petrographische Mitteilungen, 10. p.374-476. doi:10.5169/SEALS-11641
Berek, M.; Strieder, F. (1933) Beiträge zur Kenntnis der komplexen Indikatrix rhombischer schwach absorbierender Kristalle. Zeitschrift für Kristallographie, 86 (1-6). p.212-224. doi:10.1524/zkri.1933.86.1.212
Schoßberger, F. (1942) Über die Umwandlung des Titandioxyds. Zeitschrift für Kristallographie, 104 (1-6). 358-374 doi:10.1524/zkri.1942.104.1.358
MITSUHASHI, T., WATANABE, M. (1978) Brookite formation from precipitates containing calcium ions. Mineralogical Journal, 9 (4) 236-240 doi:10.2465/minerj.9.236
Tanaka, M. (1996) Crystallographic studies of brookite (TiO2) with synchrotron radiation. Acta Crystallographica Section A Foundations of Crystallography, 52 (a1). p.C321. doi:10.1107/s0108767396086667
Nagase, Takako, Ebina, Takeo, Iwasaki, Takashi, Hayashi, Hiromichi, Onodera, Yoshio, Chatterjee, Maya (1999) Hydrothermal Synthesis of Brookite. Chemistry Letters, 28 (9). 911-912 doi:10.1246/cl.1999.911
Bastow, T. J.; Doran, G.; Whitfield, H. J. (2000) Electron Diffraction and 47,49Ti and 17O NMR Studies of Natural and Synthetic Brookite. Chemistry of Materials, 12 (2). p.436-439. doi:10.1021/cm990486m
Lee, Burtrand I., Wang, Xinyu, Bhave, Radhika, Hu, Michael (2006) Synthesis of brookite TiO2 nanoparticles by ambient condition sol process. Materials Letters, 60. 1179-1183 doi:10.1016/j.matlet.2005.10.114
Huberty, Jason, Xu, Huifang (2008) Kinetics study on phase transformation from titania polymorph brookite to rutile. Journal of Solid State Chemistry, 181. 508-514 doi:10.1016/j.jssc.2007.12.015
Hu, Wanbiao; Li, Liping; Li, Guangshe; Tang, Changlin; Sun, Lang (2009) High-Quality Brookite TiO2 Flowers: Synthesis, Characterization, and Dielectric Performance. Crystal Growth & Design, 9 (8). p.3676-3682. doi:10.1021/cg9004032
Štengl, Václav, Králová, Daniela (2011) Photoactivity of brookite–rutile TiO2 nanocrystalline mixtures obtained by heat treatment of hydrothermally prepared brookite. Materials Chemistry and Physics, 129. 794-801 doi:10.1016/j.matchemphys.2011.05.006
Xu, Jinlei; Wu, Shufang; Jin, Jingpeng; Peng, Tianyou (2016) Preparation of brookite TiO2 nanoparticles with small sizes and the improved photovoltaic performance of brookite-based dye-sensitized solar cells. Nanoscale, 8 (44). p.18771-18781. doi:10.1039/c6nr07185f
Localities for Brookite
Showing 918 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.
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Kharan District, Balochistan, Pakistan