Meionite Mineral Data
General Meionite Information
Chemical Formula:
Ca4Al6Si6O24CO3
Composition:
Molecular Weight = 934.71 gm
Calcium 17.15 % Ca 24.00 % CaO
Aluminum 17.32 % Al 32.73 % Al2 O3
Silicon 18.03 % Si 38.57 % SiO2
Carbon 1.28 % C 4.71 % CO2
Oxygen 46.22 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Ca4 Al6 Si6 O24 (CO3 )
Environment:
Small cavities in limestone ejecta blocks. Forms a series with marialite.
IMA Status:
Valid Species (Pre-IMA) 1801
Locality:
Mte. Somma, Vesuvius, Italy. Link to MinDat.org Location Data.
Name Origin:
From the Greek for "less", referring to its less acute pyramidal form compared with vesuvianite.
Name Pronunciation:
Meionite
Synonym:
ICSD 2628
PDF 44-1399
Wernerite
Meionite Image
Images:
Images:
Meionite Crystallography
Axial Ratios:
a:c = 1:0.62071
Cell Dimensions:
a = 12.26, c = 7.61, Z = 2; V = 1,143.84 Den(Calc)= 2.71
Crystal System:
Tetragonal - Dipyramidal H-M Symbol (4/m) Space Group: P 4/m
X Ray Diffraction:
By Intensity(I/Io ): 3.464(1), 3.069(0.7), 3.824(0.6),
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Physical Properties of Meionite
Cleavage:
{???} Distinct, {???} Indistinct
Color:
Bluish, Brownish, Colorless, Violet, Greenish.
Density:
2.66 - 2.73, Average = 2.69
Diaphaneity:
Transparent to subtranslucent
Fracture:
Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Habit:
Columnar - Forms columns
Habit:
Fibrous - Crystals made up of fibers.
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Hardness:
5-6 - Between Apatite and Orthoclase
Luminescence:
Fluorescent, Short UV=yellow-white, Long UV=red.
Luster:
Vitreous - Resinous
Streak:
colorless
Optical Properties of Meionite
Gladstone-Dale:
CI meas = -0.02 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = -0.014 (Superior) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2113,KPDmeas = 0.2124,KC = 0.2083 Ncalc = 1.55 - 1.57
Optical Data:
Uniaxial (-), e=1.55-1.56, w=1.58-1.6, bire=0.0300-0.0400.
Calculated Properties of Meionite
Electron Density:
Bulk Density (Electron Density)=2.69 gm/cc note: Specific Gravity of Meionite =2.71 gm/cc.
Fermion Index:
Fermion Index = 0.0090139831 Boson Index = 0.9909860169
Photoelectric:
PEMeionite = 3.33 barns/electronU=PEMeionite x r Electron Density= 8.95 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Meionite is Not Radioactive
Meionite Classification
Dana Class:
76.03.01.02 (76) Tectosilicate Al-Si Framework
(76.03) with other Be/Al/Si frameworks
(76.03.01) Scapolite group
76.03.01.00 Scapolite * (Na,Ca)4[Al3Si9O24]Cl P 41 /n 4/m
76.03.01.01 Marialite Na4Al3Si9O24Cl I 4/m 4/m
76.03.01.02 Meionite Ca4Al6Si6O24CO3 P 4/m 4/m
76.03.01.03 Silvialite ! (Ca,Na)4Al6Si6O24(SO4,CO3) I 4/m 4/m
Strunz Class:
09.FB.15 09 - SILICATES (Germanates)
09.F - Tektosilicates without Zeolitic H2O
09.FB -Tektosilicates with additional anions
09.FB.15 Meionite Ca4Al6Si6O24CO3 P 4/m 4/m
09.FB.15 Marialite Na4Al3Si9O24Cl I 4/m 4/m
09.FB.15 Scapolite * (Na,Ca)4[(Al,Si)12O24]Cl P 41 /n 4/m
09.FB.15 Silvialite ! (Ca,Na)4Al6Si6O24(SO4,CO3) I 4/m 4/m
Other Meionite Information
References:
NAME( Dana8) PHYS. PROP.(www.saint-hilaire.ca) OPTIC PROP.(Ford32)
See Also:
Links to other databases for Meionite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - Franklin Minerals(Dunn)
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - HyperPhysics
14 - MinDAT
15 - Mineralienatlas (Deutsch)
16 - Online Mineral Museum
17 - QUT Mineral Atlas
18 - Ruff.Info
19 - WWW-MINCRYST
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Meionite
Ca4Al6Si6O24CO3
Dana No: 76.03.01.02 Strunz No: 09.FB.15
Locality:
Notes:
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