Mindat Logo
Home Page Log In Message Board The Mindat Directory
Register Search Pages Mineral Chatroom The Mindat Store

Halloysite

This page is currently not sponsored. Click here to sponsor this page.
Big Photo

Cuprian Halloysite
Sounion Mine No. 06 ("Exi Mine"), Agia Varvara Mines (St Barbara Mines), Sounion Area, Lavrion District Mines, Lavrion (Laurion; Laurium) District, Attikí (Attica; Attika) Prefecture, Greece
© Steve Rust

Show Halloysite Photos (21)



Formula:
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
System:MonoclinicColour:White to tan, sometimes ...
Hardness:1 - 2
Member of:Serpentine Group
Name:Named in 1826 after the Belgian geologist Omalius d'Halloy.


Typically found as earthy to somewhat waxy looking extremely fine-grained clayey masses, white to tan and also occassionally bluish or greenish.

The name halloysite stands for the two grandfathered and distinct species Halloysite-7Å and Halloysite-10Å.
Halloysite-10Å is also known as "endellite" in European literature and considered to be a hydrated mineral - the "hydrated halloysite" of North American literature.

"Metahalloysite" (= Halloysite-7Å) is dehydrated halloysite, and characterised by a reduced interlayer spacing.

Originally reported from Angleur, Liège, Liège Province, Belgium.




Classification of Halloysite

IMA status:Not Approved
Explanation of status:Confusion exists between "halloysite" and "endellite." Most European literature has "halloysite" as Al2Si2O5(OH)4 · 2H2O (= Halloysite-10Å) and calls it "endellite." Most North American literature (not Dana 8th...) has it as Al2Si2O5(OH)4 (= Halloysite-7Å) - with the hydrated variety.
Strunz 8th edition ID:8/H.25-40
Nickel-Strunz 10th (pending) edition ID:9.ED.10

9 : SILICATES (Germanates)
E : Phyllosilicates
D : Phyllosilicates with kaolinite layers composed of tetrahedral and octahedral nets
Dana 7th edition ID:71.1.1.4
Dana 8th edition ID:71.1.1.4

71 : PHYLLOSILICATES Sheets of Six-Membered Rings
1 : Sheets of 6-membered rings with 1:1 layers
Hey's CIM Ref.:15.10

15 : Silicates of Aluminum
mindat.org URL:http://www.mindat.org/min-1808.html
Please feel free to link to this page.

Occurrences of Halloysite

Geological Setting:Halloysite is found in widely varied environments, including as an alteration of basaltic rocks, in hydrothermally altered fissure deposits in monzonites; it is also derived from feldspars, chlorites, micas, rhyolites, granites, volcanic ash, tuffs and pumices. More rarely found in granitic pegmatites, bauxites or laterites, and in some marine and glacial clays.

Physical Properties of Halloysite

Lustre:Waxy, Earthy
Diaphaneity (Transparency):Translucent, Opaque
Colour:White to tan, sometimes greenish or bluish, also chocolate brown to reddish.
Streak:Paler than the color, or white.
Hardness (Mohs):1 - 2
Fracture:Sub-Conchoidal
Density (measured):2 - 2.65 g/cm3
Density (calculated):2.14 g/cm3

Crystallography of Halloysite

Crystal System:Monoclinic
Class (H-M):m - Domatic
Space Group:Bb {B1 1b} {Cc} {C1c1}
Cell Parameters:a = 5.14Å, b = 8.9Å, c = 7.214Å
β = 99.7°
Ratio:a:b:c = 0.578 : 1 : 0.811
Unit Cell Volume:V 325.29 ų (Calculated from Unit Cell)
Z:2
Morphology:Typically found as extremely fine-grained clayey masses. The two "forms" Halloysite-7Å and Halloysite-10Å are the most common. It has a tubular morphology at the nanometer scale.
X-Ray Powder Diffraction:
d-spacingIntensity
Halloysite-7A (1)
(
7.5(90)
4.42(100)
3.63(90)
2.56(80)
1.68(80)
1.48(90)
1.28(70)
1.23(70)
________(
(
Halloysite-7A (2)
(
7.3(65)
4.42(100)
3.62(60)
2.56(25)
2.37(<10)
1.68(20)
1.48(30)
_________(
(
Halloysite-10A (1)
(
10.1(90)
4.42(100)
3.34(90)
2.56(80)
1.68(80)
1.48(90)
1.28(70)
1.23(70)
________(
(
Halloysite-10A (2)
(
10.0(100)
4.36(70)
3.35(40)
2.54(35)
1.67(10)
1.48(30)
1.28(10)
(
(

Optical Data of Halloysite

Type:Biaxial
RI values: nα = 1.553 - 1.565 nβ = 1.559 - 1.569 nγ = 1.560 - 1.570
Maximum Birefringence:δ = 0.007

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Low
Dispersion:r < v moderate

Chemical Properties of Halloysite

Formula:
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
Essential elements:Al, H, O, Si
All elements listed in formula:Al, H, O, Si
Common Impurities:Ti,Ca,Na,K,Fe,Cr,Mg,Ni,Cu

Relationship of Halloysite to other Species

Member of:Serpentine Group
Other Members of Group:

- +
Amesite
Mg
 
2
Al(AlSiO
 
5
)(OH)
 
4
Antigorite
Mg
 
3
(Si
 
2
O
 
5
)(OH)
 
4
Berthierine
(Fe,Fe,Mg)
 
2-3
((Si,Al)
 
2
O
 
5
)(OH)
 
4
Brindleyite
(Ni,Mg,Fe)
 
2
(Al(Si,Al)O
 
5
)(OH)
 
4
Caryopilite
(Mn,Mg)
 
3
(Si
 
2
O
 
5
)(OH)
 
4
Chrysotile
Mg
 
3
(Si
 
2
O
 
5
)(OH)
 
4
Clinochrysotile
Cronstedtite
Fe
2+
2
Fe
3+
 
((Si,Fe
3+
 
)
 
2
O
 
5
)(OH)
 
4
Dickite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
Fraipontite
(Zn,Al)
 
3
((Si,Al)
 
2
O
 
5
)(OH)
 
4
Greenalite
Fe
 
2-3
(Si
 
2
O
 
5
)(OH)
 
4
Kaolinite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
Kellyite
Mn
2+
2
Al(AlSiO
 
5
)(OH)
 
4
Lizardite
Mg
 
3
(Si
 
2
O
 
5
)(OH)
 
4
Manandonite
LiAl
 
4
(BSi
 
3
O
 
10
)(OH)
 
6
Nacrite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
Népouite
(Ni,Mg)
 
3
(Si
 
2
O
 
5
)(OH)
 
4
Odinite
(Fe,Mg,Al,Fe,Ti,Mn)
 
2.4
((Si,Al)
 
2
O
 
5
)(OH)
 
4
Orthochrysotile
Parachrysotile
Pecoraite
Ni
 
3
(Si
 
2
O
 
5
)(OH)
 
4
Related Minerals - Nickel-Strunz Grouping):

- +
9.ED.05Dickite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.05Kaolinite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.05Nacrite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.05Odinite
(Fe,Mg,Al,Fe,Ti,Mn)
 
2.4
((Si,Al)
 
2
O
 
5
)(OH)
 
4
9.ED.10Hisingerite
Fe
3+
2
(Si
 
2
O
 
5
)(OH)
 
4
 · 2H
 
2
O
9.ED.10Halloysite-7Å
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Amesite
Mg
 
2
Al(AlSiO
 
5
)(OH)
 
4
9.ED.15Antigorite
Mg
 
3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Berthierine
(Fe,Fe,Mg)
 
2-3
((Si,Al)
 
2
O
 
5
)(OH)
 
4
9.ED.15Brindleyite
(Ni,Mg,Fe)
 
2
(Al(Si,Al)O
 
5
)(OH)
 
4
9.ED.15Caryopilite
(Mn,Mg)
 
3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Chrysotile
Mg
 
3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Cronstedtite
Fe
2+
2
Fe
3+
 
((Si,Fe
3+
 
)
 
2
O
 
5
)(OH)
 
4
9.ED.15Fraipontite
(Zn,Al)
 
3
((Si,Al)
 
2
O
 
5
)(OH)
 
4
9.ED.15Greenalite
Fe
 
2-3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Kellyite
Mn
2+
2
Al(AlSiO
 
5
)(OH)
 
4
9.ED.15Lizardite
Mg
 
3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Manandonite
LiAl
 
4
(BSi
 
3
O
 
10
)(OH)
 
6
9.ED.15Népouite
(Ni,Mg)
 
3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Pecoraite
Ni
 
3
(Si
 
2
O
 
5
)(OH)
 
4
9.ED.15Guidottiite
Mn
 
2
Fe
3+
 
(Fe
3+
 
SiO
 
5
)(OH)
 
4
9.ED.20Allophane
(Al
 
2
O
 
3
)(SiO
 
2
)
 
1.3-2
 · 2.5-3H
 
2
O
9.ED.20Chrysocolla
Cu
 
2-x
Al
 
x
(H
 
2-x
Si
 
2
O
 
5
)(OH)
 
4
 · nH
 
2
O (x < 1)
9.ED.20Imogolite
Al
 
2
SiO
 
3
(OH)
 
4
9.ED.20Neotocite
(Mn,Fe,Mg)SiO
 
3
 · H
 
2
O
9.ED.25Bismutoferrite
Fe
3+
2
Bi(SiO
 
4
)
 
2
(OH)
9.ED.25Chapmanite
Fe
3+
2
Sb
3+
 
(SiO
 
4
)
 
2
(OH)
Related Minerals - Hey's Index Grouping:

- +
15.1Andalusite
Al
 
2
(SiO
 
4
)O
15.2Kyanite
Al
 
2
(SiO
 
4
)O
15.3Sillimanite
Al
 
2
(SiO
 
4
)O
15.4Mullite
Al
 
4+2x
Si
 
2-2x
O
 
10-x
15.5Pyrophyllite
Al
 
2
(Si
 
4
O
 
10
)(OH)
 
2
15.6Dickite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
15.7Nacrite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
15.8Kaolinite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
15.9Metahalloysite
15.11Allophane
(Al
 
2
O
 
3
)(SiO
 
2
)
 
1.3-2
 · 2.5-3H
 
2
O
Related Minerals - Dana Grouping):

- +
71.1.1.1Dickite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
71.1.1.2Kaolinite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4
71.1.1.3Nacrite
Al
 
2
(Si
 
2
O
 
5
)(OH)
 
4

Other Names for Halloysite

Synonyms:
ConfolensiteGalapectiteGlageriteGlossecolliteGummite (of Breithaupt)
Halloysite (of Berthier)IndianaiteLenziniteMountain SoapSmectite (of Salvetat)
Other Languages:
Esperanto:Halojzito
German:Galapectit
Galapektit
Glagerit
Glossecollit
Halloysit
Hydrohalloysit
Hydrokaolin
Indianait
Lenzinit
Simplified Chinese:多水高岭石
Spanish:Galapectita
Glagerita
Glossecollita
Halloysita
Hydrohalloysita
Indianaita
Lenzinita
Varieties:
Chrome-HalloysiteCuprian HalloysiteFerrian HalloysiteZirconian Halloysite

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Industrial Uses:Used in applications similar to those of kaolinite, such as high-strength cements and high-quality ceramics.

References for Halloysite

Reference List:

- +
Clays and Clay Minerals (1978): 26: 25.

Gaines, Richard V., H. Catherine, W. Skinner, Eugene E. Foord, Brian Mason, Abraham Rosenzweig (1997), Dana's New Mineralogy : The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana: 1411.

Internet Links for Halloysite

Search Engines:
  • Look for Halloysite on Google
  • Look for Halloysite images on Google
    • External Links:
  • Halloysite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • Buy RARE Minerals from Rocks of Africa
  • Fine Minerals from Weinrich Minerals, Inc.
  • Search for Halloysite from all mineral dealers at minfind.com
  • webminerals
  • Top quality minerals from Kristalle of California
  • Find Halloysite on www.crystalclassics.co.uk
  • SpiriferMinerals.com - high quality low prices
  • High-end worldwide specimens & outstanding customer service
  • Search for minerals at Heliodor
  • Wilensky Fine Minerals
  • Edwards Minerals - Fine Specimens
  • Rare and Unusual minerals at Mineralogical Research Company
    • Jobs:
  • Mining & Geology Jobs

    • Localities for Halloysite

    The 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.
    Show Locality List (481 Items)
    Mineral and/or Locality
    Search Google
     
    Copyright © Jolyon Ralph and Ida Chau 1993-2011. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
    Current server date and time: 2nd Sep 2011 03:10:28
    Mineral and Locality Search
    Mineral:
    and/or Locality:
    Options
    Fade toolbar when not in focusFix toolbar to bottom of page
    Hide Social Media Links
    Slideshow frame delay seconds
    Locality Updated: Pegmatite No. 6, Etusis Farm 75, Karibib District, Erongo Region, NamibiaFrom Debbie Woolf, 18th Feb 2012 00:40:42