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Parascandolaite
A valid IMA mineral species
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About Parascandolaite
Antonio Parascandola
Formula:
KMgF3
Colour:
Colourless, white
Lustre:
Vitreous
Specific Gravity:
3.11
Crystal System:
Isometric
Name:
Named in honor of Antonio Parascandola (27 July 1902, Procida, Naples, Campania, Italy - 30 March 1977, Portici, Naples, Campania, Italy), professor of mineralogy, geology and later volcanology and physical geography at the Pozzuoli aeronautical academy, at the Istituto di Mineralogia della FacoltĂ di Scienze of Napoli and at the Istituto di Mineralogia e geologia della FacoltĂ di agraria of Portici (Napoli). He made detailed observations about the conditions of formation of the minerals in the fumaroles. The mineral was found in scoria formed during the 1944 eruption that Parascandola studied.
The mineral, isotypic to cubic perovskites, is the natural analog of the synthetic fluoride KMgF3 and is related to neighborite, NaMgF3. Parascandolaite probably corresponds to unnamed mineral UM1960-02-F:KMg (Smith and Nickel, 2007).
Unique Identifiers
Mindat ID:
45939
Long-form identifier:
mindat:1:1:45939:0
IMA Classification of Parascandolaite
Approved
Approval year:
2013
First published:
2014
Classification of Parascandolaite
3.AA.35
3 : HALIDES
A : Simple halides, without H2O
A : M:X = 1:1, 2:3, 3:5, etc.
3 : HALIDES
A : Simple halides, without H2O
A : M:X = 1:1, 2:3, 3:5, etc.
Mineral Symbols
As of 2021 there are now IMAâCNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Psd | IMAâCNMNC | Warr, L.N. (2021). IMAâCNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Parascandolaite
Vitreous
Transparency:
Transparent
Colour:
Colourless, white
Cleavage:
Perfect
on {100}
on {100}
Density:
3.11(1) g/cm3 (Measured) 3.123 g/cm3 (Calculated)
Optical Data of Parascandolaite
Type:
Isotropic
RI values:
n = 1.395(5)
Surface Relief:
Very High (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Chemistry of Parascandolaite
Mindat Formula:
KMgF3
Element Weights:
Elements listed:
Crystallography of Parascandolaite
Crystal System:
Isometric
Class (H-M):
m3m(4/m32/m) - Hexoctahedral
Space Group:
Pm3m
Setting:
Pm3m
Cell Parameters:
a = 4.0032(9) Å
Unit Cell V:
64.14 Ă
Âł
Z:
1
Morphology:
Cubic crystals.
Twinning:
No twinning was observed.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.831 Ă | (83) |
| 2.311 Ă | (78) |
| 2.001 Ă | (100) |
| 1.633 Ă | (35) |
| 1.415 Ă | (56) |
| 1.267 Ă | (16) |
| 1.206 Ă | (22) |
Reference:
Comments:
Sample from the type locality.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 36 : Carbonatites, kimberlites, and related igneous rocks | |
| Stage 7: Great Oxidation Event | <2.4 |
| 45b : [Other oxidized fumarolic minerals] |
Geological Setting:
Microinclusions in diamond
Type Occurrence of Parascandolaite
General Appearance of Type Material:
cubic crystals up to 0.5 mm in length
Place of Conservation of Type Material:
Deposited in the Reference Collection of the Dipartimento di Chimica, UniversitĂ degli Studi di Milano, Italy, specimen number 2013â2014.
Geological Setting of Type Material:
volcanic sublimate at Vesuvius volcano on 1944 eruption lava scoria. Parascandolaite formed by reaction of the fumarolic gases containing hydrofluoric acid with the K-rich host rock.
Associated Minerals at Type Locality:
Synonyms of Parascandolaite
Other Language Names for Parascandolaite
Dutch:Parascandolaiet
German:Parascandolait
Relationship of Parascandolaite to other Species
Other Members of Neighborite Subgroup:
| Neighborite | NaMgF3 | Orth. mmm(2/m2/m2/m) : Pnma |
Common Associates
Related Minerals - Strunz-mindat Grouping
| 3.AA. | Brontesite | (NH4)3PbCl5 |
| 3.AA.05 | Marshite | CuI |
| 3.AA.05 | Nantokite | CuCl |
| 3.AA.05 | 'UM1999-11:I:CuS' | Cu(I,S) |
| 3.AA.05 | Miersite | (Ag,Cu)I |
| 3.AA.10 | Tocornalite | (Ag,Hg)I (?) |
| 3.AA.10 | Iodargyrite | AgI |
| 3.AA.15 | Bromargyrite | AgBr |
| 3.AA.15 | Chlorargyrite | AgCl |
| 3.AA.20 | Sylvite | KCl |
| 3.AA.20 | Halite | NaCl |
| 3.AA.20 | Villiaumite | NaF |
| 3.AA.20 | Carobbiite | KF |
| 3.AA.20 | Griceite | LiF |
| 3.AA.25 | 'UM1998-03-Cl:Tl' | TlCl |
| 3.AA.25 | Nataliyamalikite | TlI |
| 3.AA.25 | Lafossaite | Tl(Cl,Br) |
| 3.AA.25 | Salammoniac | NH4Cl |
| 3.AA.30 | Calomel | [Hg2]2+Cl2 |
| 3.AA.30 | Moschelite | [Hg2]2+I2 |
| 3.AA.30 | Kuzminite | HgBr |
| 3.AA.35 | Neighborite | NaMgF3 |
| 3.AA.40 | Javorieite | KFeCl3 |
| 3.AA.40 | Chlorocalcite | KCaCl3 |
| 3.AA.45 | Kolarite | PbTeCl2 |
| 3.AA.50 | Radhakrishnaite | PbTe3(Cl,S)2 |
| 3.AA.55 | Challacolloite | KPb2Cl5 |
| 3.AA.60 | Hephaistosite | TlPb2Cl5 |
| 3.AA.90 | Pseudocotunnite | K2PbCl4 |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, ÎČ, Îł |
| Thorium (Th) | 0.0000% | 0 | α, ÎČ, Îł |
| Potassium (K) | 32.4741% | 10,067 | ÎČ, Îł |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000â3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 ”Sv/year. Note that natural background radiation averages around 2400 ”Sv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: â
| Distance | Dose rate | Risk |
|---|---|---|
| 1âŻcm | ||
| 10âŻcm | ||
| 1âŻm |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Fluorescence of Parascandolaite
No fluorescence was observed under either short- or long-wave ultraviolet radiation.
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.
Internet Links for Parascandolaite
mindat.org URL:
https://www.mindat.org/min-45939.html
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External Links:
Mineral Dealers:
References for Parascandolaite
Reference List:
Alcala, R., Koumvakalis, N., Sibley, W. A. (1975) The self-trapped hole and thermoluminescence in KMgF3. physica status solidi (a), 30 (2). 449-456 doi:10.1002/pssa.2210300203
Jones, Leonie E. A. (1979) Pressure and temperature dependence of the single crystal elastic moduli of the cubic perovskite KMgF3. Physics and Chemistry of Minerals, 4 (1) 23-42 doi:10.1007/bf00308357
Komar, V.K., Gektin, A.V., Ivanov, N.P., Nesterenko, Y.A., Shiran, N.V. (1996) Growth and study of properties of pure and rare-earth-doped KMgF3 crystals. Journal of Crystal Growth, 166 (1). 419-422 doi:10.1016/0022-0248(96)00095-4
Lal, Banwari, Bamzai, K.K, Kotru, P.N (2001) Topographic and etching investigations on melt grown doped KMgF3 crystals. Materials Chemistry and Physics, 69. 99-112 doi:10.1016/s0254-0584(00)00360-6
Lal, Banwari, Bamzai, K.K, Kotru, P.N (2003) Mechanical characteristics of melt grown doped KMgF3 crystals. Materials Chemistry and Physics, 78. 202-207 doi:10.1016/s0254-0584(02)00342-5
Lal, Banwari, Khosa, S.K, Tickoo, Ravender, Bamzai, K.K, Kotru, P.N (2004) Dielectric characteristics of melt grown doped KMgF3 crystals. Materials Chemistry and Physics, 83. 158-168 doi:10.1016/j.matchemphys.2003.09.011
Sahnoun, M., Zbiri, M., Daul, C., Khenata, R., Baltache, H., Driz, M. (2005) Full potential calculation of structural, electronic and optical properties of KMgF3. Materials Chemistry and Physics, 91. 185-191 doi:10.1016/j.matchemphys.2004.11.019
Mitchell, Roger H., Cranswick, Lachlan M. D., Swainson, Ian (2006) Neutron diffraction determination of the cell dimensions and thermal expansion of the fluoroperovskite KMgF3 from 293 to 3.6Â K. Physics and Chemistry of Minerals, 33 (8) 587-591 doi:10.1007/s00269-006-0106-x
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) New minerals and nomenclature modifications approved in 2013. CNMNC Newsletter No 18. Mineralogical Magazine, 77 (8) 3249-3258 doi:10.1180/minmag.2013.077.8.15
Demartin, Francesco, Campostrini, Italo, Castellano, Carlo, Russo, Massimo (2014) Parascandolaite, KMgF3, a new perovskite-type fluoride from Vesuvius. Physics and Chemistry of Minerals, 41 (6) 403-407 doi:10.1007/s00269-014-0668-y
Kaminsky, Felix V.; Wirth, Richard; Schreiber, Anja (2015) A microinclusion of lower-mantle rock and other minerals and nitrogen lower mantle inclusions in a diamond. The Canadian Mineralogist, 53 (1). 83-104 doi:10.3749/canmin.1400070
Mitchell, Roger H., Welch, Mark D., Chakhmouradian, Anton R. (2017) Nomenclature of the perovskite supergroup: A hierarchical system of classification based on crystal structure and composition. Mineralogical Magazine, 81 (3) 411-461 doi:10.1180/minmag.2016.080.156
Localities for Parascandolaite
Showing 8 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
â - Click for references and 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).
All localities listed without proper references should be considered as questionable.
Brazil | |
| Kaminsky et al. (2015) +1 other reference |
Italy (TL) | |
| Demartin et al. (2014) |
| Demartin et al. (2014) +1 other reference |
| Demartin et al. (2014) | |
| Demartin et al. (2014) +1 other reference | |
Russia | |
| Starikova et al. (2017) |
| Sharygin +9 other references |
Tanzania | |
| Mitchell (1997) |
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Vesuvius fumaroles on eastern crater rim, Ottaviano, Metropolitan City of Naples, Campania, Italy