VOOZH about

URL: https://www.mindat.org/min-1890.html

⇱ Hewettite: Mineral information, data and localities.

👁 Image
Now Featuring: The Bruce Carter Collection at Heritage Auctions, Live May 16th
Log InRegister
AboutSupport UsPhotosDiscussionsSearchLearnMore

Hewettite

A valid IMA mineral species - grandfathered
Sponsorship for this page has expired!

About HewettiteHide

This section is currently hidden. Click the show button to view.
Formula:
CaV6O16 · 9H2O
Colour:
Deep red; chocolate brown (upon exposure); red to orange in transmitted light
Lustre:
Adamantine, Silky
Specific Gravity:
2.51 - 2.61
Crystal System:
Monoclinic
Member of:
Name:
Named in honor of Donnel Foster Hewett (June 24, 1881, Irwin, Pennsylvania - February 5, 1971), U.S. Geological Survey, who studied the mineralogy of Mina Ragra, Cerro de Pasco, Peru. He was primarily responsible for the discovery of that, the largest vanadium deposit in the world.
A secondary mineral resulting from the alteration of patronite (TL), or from the alteration of less-oxidized vanadium minerals.

May reversibly dehydrate to metahewettite.


Unique IdentifiersHide

This section is currently hidden. Click the show button to view.
Mindat ID:
1890
Long-form identifier:
mindat:1:1:1890:2

IMA Classification of HewettiteHide

This section is currently hidden. Click the show button to view.
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
CaV5+6O16 · 9H2O
First published:
1914

Classification of HewettiteHide

This section is currently hidden. Click the show button to view.
4.HE.15

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
H : V[5,6] Vanadates
E : Phyllovanadates
47.3.1.1

47 : VANADIUM OXYSALTS
3 : Hydrated Normal Vanadium Oxysalts
21.2.4

21 : Vanadates (and vanadates with arsenate or phosphate)
2 : Vanadates of Mg, Ca, Sr or Ba

Mineral SymbolsHide

This section is currently hidden. Click the show button to view.
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
HewIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of HewettiteHide

This section is currently hidden. Click the show button to view.
Adamantine, Silky
Transparency:
Transparent
Colour:
Deep red; chocolate brown (upon exposure); red to orange in transmitted light
Comment:
Extremely soft.
Density:
2.51 - 2.61 g/cm3 (Measured)    2.67 g/cm3 (Calculated)

Optical Data of HewettiteHide

This section is currently hidden. Click the show button to view.
Type:
Biaxial (-)
RI values:
nα = 1.77 nβ = 2.18 nγ = 2.35 - 2.4
Max. Birefringence:
δ = 0.580 - 0.630
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.

Surface Relief:
Moderate
Dispersion:
r > v distinct
Optical Extinction:
Parallel. Z = c.
Pleochroism:
Visible
Comments:
X = Y = Light yellow-orange; Z = Dark red.
Comments:
2V medium

Chemistry of HewettiteHide

This section is currently hidden. Click the show button to view.
Mindat Formula:
CaV6O16 · 9H2O
Element Weights:
Element% weight
O52.364 %
V40.014 %
Ca5.247 %
H2.375 %

Calculated from ideal end-member formula.

Crystallography of HewettiteHide

This section is currently hidden. Click the show button to view.
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Cell Parameters:
a = 12.29 Å, b = 3.59 Å, c = 11.174 Å
β = 97.24°
Ratio:
a:b:c = 3.423 : 1 : 3.113
Unit Cell V:
489.08 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Crystals acicular and as fibers, elongated and intertwined parallel [010]; nodular aggregates, fracture fillings, and coatings.

Crystal StructureHide

This section is currently hidden. Click the show button to view.
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File    Best | x | y | z | a | b | c
Rotation
Stop | Start
Labels
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0005224HewettiteEvans H T (1989) The crystal structure of hewettite The Canadian Mineralogist 27 181-188👁 Image
1989Colorado Plateau, USA0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

This section is currently hidden. Click the show button to view.
Powder Diffraction Data:
d-spacingIntensity
11.03 Å(100)
5.63 Å(12)
5.53 Å(35)
3.660 Å(14)
3.091 Å(20)
2.574 Å(12)
2.164 Å(25)
Comments:
Monument No. 2 mine, Arizona, USA. The data are from Bayliss (1982).

Geological EnvironmentHide

This section is currently hidden. Click the show button to view.
Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]
47e : [Vanadates, chromates, manganates]
Geological Setting:
Colorado Plateau-type U-V deposits

Type Occurrence of HewettiteHide

This section is currently hidden. Click the show button to view.
General Appearance of Type Material:
Lumpy aggregates, composed of needles usually less than 0.01 x 0.2 mm.
Place of Conservation of Type Material:
U.S. National Museum of Natural History, Washington, D.C., USA: #87459.
Geological Setting of Type Material:
Very rich vanadium deposit in sedimentary rocks.
Associated Minerals at Type Locality:

Other Language Names for HewettiteHide

This section is currently hidden. Click the show button to view.
Dutch:Hewettiet
German:Hewettit
Simplified Chinese:针钒钙石
Spanish:Hewettita
Traditional Chinese:針釩鈣石

Relationship of Hewettite to other SpeciesHide

This section is currently hidden. Click the show button to view.
Member of:
Other Members of Hewettite Group:
Barnesite(Na,Ca)V6O16 · 3H2OMon. 2/m : P2/m
Grantsite(Na,Ca)2+x(V5+,V4+)6O16 · 4H2OMon. 2/m : P21/m
Hendersonite(Ca,Sr)1.3V6O16 · 6H2OOrth.
MetahewettiteCaV6O16 · 3H2OMon. 2/m

Common AssociatesHide

This section is currently hidden. Click the show button to view.
Associated Minerals Based on Photo Data:
24 photos of Hewettite associated with TyuyamuniteCa(UO2)2(VO4)2 · 5-8H2O
23 photos of Hewettite associated with OpalSiO2 · nH2O
17 photos of Hewettite associated with GypsumCaSO4 · 2H2O
12 photos of Hewettite associated with FluelliteAl2(PO4)F2(OH) · 7H2O
12 photos of Hewettite associated with KazakhstaniteFe3+5V4+3V5+12O39(OH)9 · 9H2O
11 photos of Hewettite associated with VarisciteAlPO4 · 2H2O
10 photos of Hewettite associated with Nevadaite(Cu2+,Al,V3+)6Al8(PO4)8F8(OH)2 · 22H2O
9 photos of Hewettite associated with BaryteBaSO4
8 photos of Hewettite associated with RauviteCa(UO2)2(V10O28) · 16H2O
7 photos of Hewettite associated with QuartzSiO2

Related Minerals - Strunz-mindat GroupingHide

This section is currently hidden. Click the show button to view.
4.HE.05MelanovanaditeCa(V5+,V4+)4O10 · 5H2OTric. 1 : P1
4.HE.10ShcherbinaiteV5+2O5Orth. mmm(2/m2/m2/m) : Pmmn
4.HE.15MetahewettiteCaV6O16 · 3H2OMon. 2/m
4.HE.20BarianditeAl0.6(V5+,V4+)8O20 · 9H2OMon.
4.HE.20Corvusite(Na,K,Ca,Mg)2(V5+,V4+,Fe2+)8O20 · 6-10H2OMon. 2/m : B2/m
4.HE.20Bokite(Al,Fe)1.3(V5+,V4+,Fe3+)8O20 · 7.5H2OMon.
4.HE.20Fernandinite(Ca,K)(V5+,V4+,Fe2+)8O20 · 10H2OMon. 2/m : B2/m
4.HE.20Straczekite(Ca,K,Ba)(V5+,V4+)8O20 · 3H2OMon. 2/m : B2/m
4.HE.25HäggiteV3+V4+O2(OH)3Mon. 2/m : B2/m
4.HE.30DoloresiteV4+3O4(OH)4Mon. 2/m : B2/m
4.HE.35DuttoniteV4+O(OH)2Mon. 2/m
4.HE.40CavoiteCaV4+3O7Orth. mmm(2/m2/m2/m) : Pnma

Other InformationHide

This section is currently hidden. Click the show button to view.
Thermal Behaviour:
When heated, it passes through various color changes and melts readily.
Notes:
Reversibly dehydrates to metahewettite. Slightly soluble in water.
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 HewettiteHide

This section is currently hidden. Click the show button to view.
mindat.org URL:
https://www.mindat.org/min-1890.html
Please feel free to link to this page.

References for HewettiteHide

This section is currently hidden. Click the show button to view.
Reference List:

Localities for HewettiteHide

This section is currently hidden. Click the show button to view.

Showing 78 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the 👁 Image
symbol to view information about a locality. The 👁 Image
symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

This section is currently hidden. Click the show button to view.
👁 Image
- This locality has map coordinates listed. 👁 Image
- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. 👁 Image
- Good crystals or important locality for species. 👁 Image
- 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.
China
  • Guizhou
    • Qianxinan
      • Qinglong County
        • Dachang Sb ore field
Tron et al. (12/2022)
Kazakhstan
  • Jambyl Region
    • Talas Alatau Range (Talas Ala-Too Range)
Ankinovich et al. (1997)
  • Kyzylorda Region
    • Shieli District
Fleischer (1959) +1 other reference
  • Turkistan Region
    • Sozak District
      • Aksumbe
Pekov (1998)
Peru (TL)
  • Pasco
    • Pasco Province
      • Huayllay District
Hillebrand et al. (1914) +1 other reference
Spain
  • Canary Islands
    • Santa Cruz de Tenerife Province
      • Tenerife
        • Granadilla de Abona
Dill et al. (2023)
USA
  • Arizona
    • Apache County
      • Cane Valley Mining District
        • Yazzie Mesa
          • Monument No. 2 channel
Weeks et al. (1955) +3 other references
Isachsen (1955) +3 other references
Page et al. (1956) +4 other references
        • Lukachukai Mining District
          • White Ash Peak
Scarborough (1981)
      • Red Rock Mining District
        • Red Rock
Scarborough (1981)
    • Cochise County
      • Tombstone Mining District
Rob Bowell
    • Navajo County
      • Mineral Mining District
        • Mystery Valley
          • Monument No. 1 channel (Channel No. 36)
Evensen et al. (1958) +4 other references
Evensen et al. (1958) +3 other references
Scarborough (1981)
  • Arkansas
    • Garland County
      • Wilson Springs (Potash Sulfur Springs)
        • Union Carbide Mine
Pabst (1979) +1 other reference
Howard +1 other reference
  • Colorado
    • Mesa County
      • Calamity Mesa
Eckel et al. (1997)
      • Gateway Mining District
        • Beaver Mesa
Carnegie Museum of Natural History ...
Kampf et al. (2017)
    • Montrose County
      • Bull Canyon
        • Greagor Group
Eckel et al. (1997)
Eckel et al. (1997)
Thorne (n.d.)
Bullock (1981)
Eckel et al. (1997)
Eckel et al. (1997)
      • Gypsum Valley
Eckel et al. (1997)
Weeks et al. (1964)
Eckel et al. (1997)
      • Paradox Valley
USGS Bull 1042F +1 other reference
Eckel et al. (1997)
USGS Prof Paper 320
Palache et al. (1944)
Eckel et al. (1997)
USGS Prof Paper 320
    • San Miguel County
Kampf et al. (2019)
    • Slick Rock Mining District
www.handbookofmineralogy.org (2015)
Eckel et al. (1997)
In the collection of Alex Earl
Kampf et al. (2011)
Anthony et al. (1995)
  • Nevada
    • Eureka County
      • Carlin Trend
        • Maggie Creek Mining Subdistrict
Newmont Mining Corporation
      • Gibellini Mining District
Castor et al. (2004)
        • Fish Creek Range
Castor et al. (2004)
      • Lynn Mining District
        • Elko
Jensen et al. (1995)
Barrick Gold Corporation
  • New Mexico
    • Cibola County
      • East Grants Ridge Mining District
Weeks et al. (1964) +1 other reference
Northrop et al. (1996)
    • McKinley County
Petrov (n.d.)
    • San Juan County
Northrop et al. (1996)
        • Eastside mines
NMBGMR Open-file Report - 466. +1 other reference
  • Oregon
Lavinsky (n.d.)
  • South Dakota
    • Fall River County
USGS Bull 1063D +4 other references
        • Craven Canyon
Roberts et al. (1965)
  • Utah
    • Emery County
Young et al. (1960)
      • San Rafael Swell Mining District
Bullock (1981)
Palache et al. (1951) +4 other references
Bullock (1981)
Bullock (1981)
Bullock (1981)
    • Garfield County
DOELLING (1967) +1 other reference
    • Grand County
Bullock (1981)
Bullock (1981)
Am Min 16:273-277
Collected by Michael Cline & Michael ...
Collected by Michael Cline
Kampf et al. (2025)
        • The Poison Strip
Bullock (1981)
    • San Juan County
Page et al. (1956) +2 other references
      • La Sal Creek Mining District
Kampf et al. (2012)
Canadian Mineralogist (2001)
Carter et al. (1965) +1 other reference
Bullock (1981) +1 other reference
      • La Sal Mining District
Joe Marty Collection
  • Wyoming
    • Campbell County
Page et al. (1956) +2 other references
    • Crook County
      • Northern Black Hills Mining District
USGS Bull 1082J
Quick NavTopAbout HewettiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 4, 2026 13:09:21 Page updated: March 8, 2026 21:04:16
Go to top of page