Jennite Mineral Data
General Jennite Information
Chemical Formula:
Ca9Si6O18(OH)6•8H2O
Composition:
Molecular Weight = 1,063.37 gm
Calcium 33.92 % Ca 47.46 % CaO
Silicon 15.85 % Si 33.90 % SiO2
Hydrogen 2.09 % H 18.64 % H2 O
Oxygen 48.15 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Ca9 Si6 O18 (OH)6 •8(H2 O)
Environment:
Late stage mineral in metamorphosed limestone.
IMA Status:
Approved IMA 1966
Locality:
Crestmore Quarry, 5 miles NW of Riverside, Riverside Co. California. Link to MinDat.org Location Data.
Name Origin:
Named for Clarence Marvin Jenni (1896-1973), American mineral collector and director of the Geological Museum, University of Missouri.
Name Pronunciation:
Jennite
Jennite Image
Images:
Jennite Crystallography
Axial Ratios:
a:b:c =1.4557:1:1.5046
Cell Dimensions:
a = 10.576, b = 7.265, c = 10.931, Z = 1; alpha = 101.3°, beta = 96.98°, gamma = 109.65° V = 769.89 Den(Calc)= 2.29
Crystal System:
Triclinic - Pinacoidal H-M Symbol ( 1 ) Space Group: P1
X Ray Diffraction:
By Intensity(I/Io ): 10.5(1), 2.92(0.8), 3.04(0.6),
Physical Properties of Jennite
Cleavage:
{001} Distinct
Color:
White.
Density:
2.32 - 2.33, Average = 2.32
Habit:
Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).
Habit:
Platy - Sheet forms (e.g. micas).
Hardness:
3.5 - Copper Penny
Luminescence:
Sometimes Fluorescent, Short UV=weak white.
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Jennite
Gladstone-Dale:
CI meas = -0.033 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = -0.036 (Excellent) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2419,KPDmeas = 0.2414,KC = 0.2335 Ncalc = 1.54
Optical Data:
Biaxial (-), a=1.548-1.552, b=1.562-1.564, g=1.57-1.571, bire=0.0190-0.0220, 2V(Calc)=72-74, 2V(Meas)=74.
Calculated Properties of Jennite
Electron Density:
Bulk Density (Electron Density)=2.37 gm/cc note: Specific Gravity of Jennite =2.33 gm/cc.
Fermion Index:
Fermion Index = 0.0080927409 Boson Index = 0.9919072591
Photoelectric:
PEJennite = 4.74 barns/electronU=PEJennite x r Electron Density= 11.23 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Jennite is Not Radioactive
Jennite Classification
Dana Class:
56.02.04.11 (56) Sorosilicate Si2O7 Groups and O, OH, F. and H2O
(56.02) with cations in [4] and/or >[4] coordination
(56.02.04) Cuspidine - Wohlerite group
56.02.04.01 Baghdadite Ca3(Zr,Ti)Si2O9 P 21 /a 2/m
56.02.04.02 Burpalite Na2CaZrSi2O7F2 P 21 /a 2/m
56.02.04.03 Cuspidine Ca4Si2O7(F,OH)2 P 21 /c 2/m
56.02.04.04 Lavenite (Na,Ca)2(Mn,Fe)(Zr,Ti,Nb)Si2O7(O,OH,F) P 21 /a 2/m
56.02.04.05 Wohlerite NaCa2(Zr,Nb)Si2O7(O,OH,F)2 P 21 /m 2/m
56.02.04.06 Niocalite Ca14Nb2(Si2O7)4O6F2 Pa m
56.02.04.07 Hiortdahlite (Ca,Na,Y)3(Zr,Ti)Si2O7(F,O,OH)2 P1 1
56.02.04.08 Rosenbuschite (Ca,Na)3(Zr,Ti)Si2O8F P1 1
56.02.04.09 Hainite Na4Ca8(Ti,Zr,Mn,Fe)3Si8O28F8 P1 1
56.02.04.10 Janhaugite (Na,Ca)3(Mn,Fe)3(Ti,Zr,Nb)2Si4O15(OH,F,O)3 P 21 /n 2/m
56.02.04.11 Jennite Ca9Si6O18(OH)6•8H2O P1 1
56.02.04.12 Komarovite (Ca,Mn)2(Nb,Ti)2Si2O7(O,F)2•3.5(H2O) Unk Ortho
56.02.04.13 Natrokomarovite * Na6CaNb6[Si4O12F2•4(H2O) C mmm 2/m 2/m 2/m
56.02.04.14 Suolunite Ca2Si2O5(OH)2•(H2O) F dd2 mm2
56.02.04.15 Mongolite Ca4Nb6Si5O24(OH)10•5(H2O) Unk Tetra
56.02.04.16 Kristiansenite ! Ca2ScSn(Si2O7)(Si2O6OH) C1 1
56.02.04.17 Kochite ! Na2(Na,Ca)4Ca4(Mn,Ca)2Zr2Ti2(Si2O7)4(O,F)4F4 P1 1
56.02.04.18 Marianoite ! Na2Ca4(Nb,Zr)2(Si2O7)2(O,F)4 P 21 2/m
Strunz Class:
09.DG.20 09 - SILICATES (Germanates)
09.D - Inosilicates* Structural terminology according to Liebau (1985)
09.DG -Inosilicates with 3-periodic single and multiple chains
09.DG.20 Jennite Ca9Si6O18(OH)6•8H2O P1 1
Other Jennite Information
References:
NAME( Dana8) PHYS. PROP.(Dana8, AmMin 90:772) OPTIC PROP.(Dana8)
See Also:
Links to other databases for Jennite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
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Jennite
Ca9Si6O18(OH)6•8H2O
Dana No: 56.02.04.11 Strunz No: 09.DG.20
Locality:
Notes:
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