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Avogadrite

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About AvogadriteHide

Lorenzo Romano Amedeo Carlo Avogadro di Quaregna (Quaregga) e di Cerreto
Formula:
(K,Cs)[BF4]
Colour:
Colourless to white, yellowish to reddish when impure, colourless in transmitted light
Specific Gravity:
2.9 (Calculated)
Crystal System:
Orthorhombic
Name:
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)
3.CA.10

3 : HALIDES
C : Complex halides
A : Borofluorides
11.2.2.1

11 : HALIDE COMPLEXES
2 : AmBX4
8.12.2

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

Physical Properties of AvogadriteHide

Transparency:
Translucent
Colour:
Colourless to white, yellowish to reddish when impure, colourless in transmitted light
Density:
2.9 g/cm3 (Calculated)

Optical Data of AvogadriteHide

Type:
Biaxial (-)
RI values:
nα = 1.324 nβ = 1.325 nγ = 1.325
2V:
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:
Moderate
Dispersion:
r > v, strong

Chemical Properties of AvogadriteHide

Formula:
(K,Cs)[BF4]
IMA Formula:
KBF4

Crystallography of AvogadriteHide

Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pnma
Cell Parameters:
a = 8.6588 Å, b = 5.48 Å, c = 7.0299 Å
Ratio:
a:b:c = 1.58 : 1 : 1.283
Unit Cell V:
333.57 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Octagonal crystals, tabular to platy on {001}, may be elongated along [010] or [100].

X-Ray Powder DiffractionHide

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

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:
Malladrite2 photos of Avogadrite associated with Malladrite on mindat.org.
Ferruccite1 photo of Avogadrite associated with Ferruccite on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

3.CA.05FerrucciteNa[BF4]Orth.
3.CA.10Barberiite(NH4)[BF4]Orth. mmm (2/m 2/m 2/m) : Pnma

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

8.12.1FerrucciteNa[BF4]Orth.
8.12.3MalladriteNa2[SiF6]Trig.
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.
Notes:
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

ⓘ - 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 Province
      • 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
  • 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.
Russia
 
Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 32
Mineral and/or Locality  
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