Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery


This page is currently not sponsored. Click here to sponsor this page.
(Na,Ca)2(Si,Al)5O10 · 3H2O
4 - 5
For French mineralogist Ferdinand Gonnard (1833-1923).
Zeolite Group. Natrolite Subgroup.
Most gonnardites have a disordered natrolite framework.

The compositions of and structural relationships between gonnardite and tetranatrolite remain controversial (Artioli and Galli 1999; Evans et al. 2000; Ross et al. 1992; Lee et al. 2006).

Classification of Gonnardite

Approved, 'Grandfathered' (first described prior to 1959)

9 : SILICATES (Germanates)
G : Tektosilicates with zeolitic H2O; zeolite family
A : Zeolites with T5O10 Units – The Fibrous Zeolites

1 : Zeolite group - True zeolites

16 : Silicates Containing Aluminum and other Metals
10 : Aluminosilicates of Ca and alkalis

Physical Properties of Gonnardite

Hardness (Mohs):
4 - 5

Optical Data of Gonnardite

Biaxial (+)
RI values:
nα = 1.514 nβ = 1.515 nγ = 1.520
Measured: 52° , Calculated: 50°
Max Birefringence:
δ = 0.006
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:

Chemical Properties of Gonnardite

(Na,Ca)2(Si,Al)5O10 · 3H2O
Elements listed in formula:

Crystallography of Gonnardite

Crystal System:
Cell Parameters:
a = 13.38 Å, b = 13.38 Å, c = 6.66 Å
a:b:c = 1 : 1 : 0.498
Unit Cell Volume:
V 1,192.30 ų (Calculated from Unit Cell)
Also space group I-42d, a = 13.21(1), c = 6.622(4) A.

Type Occurrence of Gonnardite

Relationship of Gonnardite to other Species

Other Members of Group:
MesoliteNa2Ca2Si9Al6O30 · 8H2O
NatroliteNa2Al2Si3O10 · 2H2O
ParanatroliteNa2Al2Si3O10 · 3H2O
ScoleciteCaAl2Si3O10 · 3H2O
9.GA.05MesoliteNa2Ca2(Si9Al6)O30 · 8H2O
9.GA.05NatroliteNa2(Si3Al2)O10 · 2H2O
9.GA.05ParanatroliteNa2(Si3Al2)O10 · 3H2O
9.GA.05ScoleciteCa(Si3Al2)O10 · 3H2O
9.GA.10Thomsonite-CaNaCa2(Al5Si5)O20 · 6H2O
9.GA.10Thomsonite-SrNaSr2Al5Si5O20 · 6-7H2O
9.GA.15EdingtoniteBa(Si3Al2)O10 · 4H2O
16.10.4Thomsonite-CaNaCa2(Al5Si5)O20 · 6H2O
16.10.6MesoliteNa2Ca2(Si9Al6)O30 · 8H2O
16.10.8Garronite-CaNaCa2.5(Si10Al6)O32 · 14H2O
16.10.9BoggsiteNa3Ca8(Si77Al19)O192 · 70H2O
16.10.10Herschelite(Na2,K2,Ca,Sr,Mg)2[Al2Si4O12]2 · 12H2O
16.10.12Fedorite(K,Na)2.5(Ca,Na)7Si16O38(OH,F)2 · 3.5H2O
16.10.13WillhendersoniteKCa(Si3Al3)O12 · 5H2O
16.10.14BarreriteNa2(Al2Si7)O18 · 6H2O
16.10.15Mordenite(Na2,Ca,K2)4(Al8Si40)O96 · 28H2O
16.10.16ReyeriteNa2Ca14Al2Si22O58(OH)8 · 6H2O
16.10.20GobbinsiteNa5(Si11Al5)O32 · 11H2O
16.10.23OffretiteKCaMg(Si13Al5)O36 · 15H2O
16.10.24PerlialiteK9NaCa(Si24Al12)O72 · 15H2O
16.10.27Sodium Dachiardite(Na2,Ca,K2)4-5Al8Si40O96 · 26H2O
16.10.28Mazzite-MgMg5(Si26Al10)O72 · 30H2O
16.10.29RoggianiteCa2BeAl2Si4O13(OH)2 · nH2O (n < 2.5)

Other Names for Gonnardite

Name in Other Languages:

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.

References for Gonnardite

Reference List:
Mazzi, F., A.O. Larsen, G. Gottardi, and E. Galli (1986) Gonnardite has the tetrahedral framework of natrolite: experimental proof with a sample from Norway. Neues Jahrb. Mineral., Monatsh., 219-228.

Nawaz, R. (1988) Gonnardite and disordered natrolite-group minerals: their distinction and relations with mesolite, natrolite and thomsonite. Mineral. Mag., 52, 207-219.

Mineralogical Magazine (1998): 62: 548.

Artioli, G. and Galli, E. (1999) Gonnardite: Re-examination of holotype material and discreditation of tetranatrolite. American Mineralogist 84, 1445-1450.

Evans, H.T., Konnert, J.A., and Ross, M. (2000) The crystal structure of tetranatrolite from Mont Saint-Hilaire, Quebec, and its chemical and structural relationship to paranatrolite and gonnardite. American Mineralogist 85, 1808-1815.

Kol’tsova, T. N. (2005) Zeolites of the natrolite-thomsonite series. Inorganic Materials, 41, 750-756.

Lee, Yongjae, Hriljac, Joseph A., Parise, John B., and Vogt, Thomas (2006) Pressure-induced hydration in zeolite tetranatrolite. American Mineralogist 91, 247-251.

Internet Links for Gonnardite URL:
Please feel free to link to this page.
The following Gonnardite specimens are currently listed for sale on

Localities for Gonnardite

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.
Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2017, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: April 28, 2017 09:26:21 Page generated: April 7, 2017 20:32:41
Go to top of page