Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch 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
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography


This page is currently not sponsored. Click here to sponsor this page.
Hide all sections | Show all sections

About AvogadriteHide

Lorenzo Romano Amedeo Carlo Avogadro di Quaregna (Quaregga) e di Cerreto
Colourless to white, yellowish to reddish when impure, colourless in transmitted light
Specific Gravity:
2.9 (Calculated)
Crystal System:
For Amadeo Avogadro (Turin August 9 1776 - Turin, July 9 1856), Professor of Physics at the University of Turin, Turin, Italy. Remembered for Avogadro's gas law and Avogadro's number.
This page provides mineralogical data about Avogadrite.

Classification of AvogadriteHide

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

C : Complex halides
A : Borofluorides

2 : AmBX4

8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
12 : Fluorborates (BF'4) and fluosilicates (SiF''6)

Physical Properties of AvogadriteHide

Colourless to white, yellowish to reddish when impure, colourless in transmitted light
2.9 g/cm3 (Calculated)

Optical Data of AvogadriteHide

Biaxial (-)
RI values:
nα = 1.324 nβ = 1.325 nγ = 1.325
Measured: 75° , Calculated: 58°
Max Birefringence:
δ = 0.001
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
r > v, strong

Chemical Properties of AvogadriteHide

IMA Formula:

Crystallography of AvogadriteHide

Crystal System:
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Cell Parameters:
a = 8.6588 Å, b = 5.48 Å, c = 7.0299 Å
a:b:c = 1.58 : 1 : 1.283
Unit Cell V:
333.57 ų (Calculated from Unit Cell)
Octagonal crystals, tabular to platy on {001}, may be elongated along [010] or [100].

X-Ray Powder DiffractionHide

Powder Diffraction Data:
3.41 Å(100)
3.26 Å(80)
3.06 Å(75)
2.068 Å(55)
3.51 Å(45)
2.801 Å(40)
2.091 Å(35)
X-ray data of synthetic K[BF4] (ICDD 16-378)

Geological EnvironmentHide

Geological Setting:
Volcanic fumaroles

Type Occurrence of AvogadriteHide

General Appearance of Type Material:
minute octagonal crystals and dense crusts
Place of Conservation of Type Material:
Natural History Museum, Paris, France (No. 126.148)
Geological Setting of Type Material:
Sublimation products around volcanic fumaroles
Associated Minerals at Type Locality:

Other Language Names for AvogadriteHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
2 photos of Avogadrite associated with MalladriteNa2[SiF6]
1 photo of Avogadrite associated with FerrucciteNa[BF4]

Related Minerals - Nickel-Strunz GroupingHide

3.CA.10Barberiite(NH4)[BF4]Orth. mmm (2/m 2/m 2/m) : Pnma

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

8.12.4HieratiteK2[SiF6]Iso. m3m (4/m 3 2/m) : Fm3m
8.12.5Cryptohalite(NH4)2[SiF6]Iso. m3m (4/m 3 2/m) : Fm3m
8.12.6Bararite(NH4)2[SiF6]Trig. 3m (3 2/m)

Other InformationHide

Thermal Behaviour:
The mineral becomes cubic above 273°C.
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.

References for AvogadriteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Carobbi (1926) Reale accademia nazionale dei Lincei, Rome, Rend.: (6), 4, 382.
Zambonini (1926) Reale accademia nazionale dei Lincei, Rome, Rend.: (6), 3, 644.
Zambonini and Coniglio (1926) Reale accademia nazionale dei Lincei, Rome, Rend.: (6), 3, 521.
American Mineralogist (1927) 12, 232.
Pesce (1930) Gazzetta chimica italiana, Rome: 60: 936.
Finbak and Hassel (1936) Zeitschrift für Physikalische Chemie, Leipzig, Berlin: 32: 433 (isometric polymorph).
Klinkenberg (1937) Recueil des travaux chimiques des Pays-Bas et de la Belgique, Leyden: 56: 36.
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged: 97-98.
Vlasov, K. A., Ed. (1966): Mineralogy of rare elements, Vol. 2, 65-66.
Brunton, G. (1969): The crystal structure of KBF4. Acta Crystallographica 25, 2161-2162.
Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 32.

Internet Links for AvogadriteHide

Localities for AvogadriteHide

This 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.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for 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 (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
Italy (TL)
  • Campania
    • Naples
      • Somma-Vesuvius Complex
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 98.
Russo, M., Punzo, I. (2004): I minerali del Somma-Vesuvio, AMI
Palache, C., Berman, H., Frondel, C. (1951) The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892. Seventh edition. John Wiley & Sons, New York, Volume II, page 98; Russo, M., and Punzo, I. (2004) I Minerali del Somma-Vesuvio. AMI Associazione Micro-mineralogica Italiana, Tipografia Fantigrafica s.r.l., Cremona, 320 pp.
  • Sicily
    • Messina Province
      • Eolie Islands (Aeolian Islands)
        • Lipari
          • Vulcano Island
GRAMACCIOLI, C.M., CAMPOSTRINI, I. (2007): Demartinite, a new natural polymorph of K2SiF6 from La Fossa crater, Vulcano, Aeolian Islands, Italy. - Canadian Mineralogist - 45, 1275-1280.
Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 32
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2020, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: May 25, 2020 04:00:52 Page generated: May 24, 2020 08:41:37
Go to top of page