Jennite Mineral Data

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 % H₂O

Oxygen 48.15 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₉Si₆O₁₈(OH)₆·8(H₂O)

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.

Jennite Image

Images:

Jennite

Comments: Bright white fibrous jennite veinlet in rock.
Location: Crestmore Quarry, Riverside County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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 - PinacoidalH-M Symbol ( 1) Space Group: P1

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 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= -0.049 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2451,KPDmeas= 0.2414,KC= 0.2335

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:

r_electron=2.37 gm/cc
note: r_Jennite=2.33 gm/cc.

Fermion Index

Fermion Index = 0.00809
Boson Index = 0.99191

Photoelectric:

PE_Jennite= 4.74 barns/electron
U=PE_Jennite x r_electron= 11.23 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Jennite is Not Radioactive

Jennite Classification

Dana Class:

56.2.4.11 (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O

(56.2)with cations in [4] and/or >[4] coordination

(56.2.4)Cuspidine - Wohlerite group

56.2.4.1 Baghdadite Ca3(Zr,Ti)Si2O9 P 2₁/a 2/m

56.2.4.2 Burpalite Na2CaZrSi2O7F2 P 2₁/a 2/m

56.2.4.3 Cuspidine Ca4Si2O7(F,OH)2 P 2₁/c 2/m

56.2.4.4 Lavenite (Na,Ca)2(Mn,Fe)(Zr,Ti,Nb)Si2O7(O,OH,F) P 2₁/a 2/m

56.2.4.5 Wohlerite NaCa2(Zr,Nb)Si2O7(O,OH,F)2 P 2₁/m 2/m

56.2.4.6 Niocalite Ca14Nb2(Si2O7)4O6F2 Pa m

56.2.4.7 Hiortdahlite (Ca,Na,Y)3(Zr,Ti)Si2O7(F,O,OH)2 P1 1

56.2.4.8 Rosenbuschite (Ca,Na)3(Zr,Ti)Si2O8F P1 1

56.2.4.9 Hainite Na4Ca8(Ti,Zr,Mn,Fe)3Si8O28F8 P1 1

56.2.4.10 Janhaugite (Na,Ca)3(Mn,Fe)3(Ti,Zr,Nb)2Si4O15(OH,F,O)3 P 2₁/n 2/m

56.2.4.11 Jennite Ca9Si6O18(OH)6·8H2O P1 1

56.2.4.12 Komarovite (Ca,Mn)2(Nb,Ti)2Si2O7(O,F)2·3.5(H2O) Unk Ortho

56.2.4.13 Na-komarovite? Na6CaNb6[Si4O12F2·4(H2O) C mmm 2/m 2/m 2/m

56.2.4.14 Suolunite Ca2Si2O5(OH)2·(H2O) F dd2 mm2

56.2.4.15 Mongolite Ca4Nb6Si5O24(OH)10·5(H2O) Unk Tetra

56.2.4.16 Kristiansenite! Ca2ScSn(Si2O7)(Si2O6OH) C1 1

56.2.4.17 Kochite! Na2(Na,Ca)4Ca4(Mn,Ca)2Zr2Ti2(Si2O7)4(O,F)4F4 P1 1

Strunz Class:

VIII/D.18-10 VIII - Silicates

VIII/D - Unclassified silicates, mostly cations of big size Na, K, Ca, Sr, Pb

VIII/D.18 - Jennite series

VIII/D.18-10 Jennite Ca9Si6O18(OH)6·8H2O P1 1

Other Jennite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8, AmMin 90:772) OPTIC PROP.(Dana8)

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Print or Cut-and-Paste your Jennite Specimen Label here :

Jennite

Ca9Si6O18(OH)6·8H2O
Dana No: 56.2.4.11 Strunz No: VIII/D.18-10
Locality:

Notes: