Jeffreyite Mineral Data

Jeffreyite Mineral Data +

General Jeffreyite Information

Chemical Formula:

(Ca,Na)2(Be,Al)Si2(O,OH)7

Composition:

Molecular Weight = 255.30 gm

Sodium 4.50 % Na 6.07 % Na₂O

Calcium 23.55 % Ca 32.95 % CaO

Beryllium 2.65 % Be 7.35 % BeO

Aluminum 2.64 % Al 4.99 % Al₂O₃

Silicon 22.00 % Si 47.07 % SiO₂

Hydrogen 0.79 % H 7.06 % H₂O

Oxygen 43.87 % O

______ ______

100.00 % 105.48 % = TOTAL OXIDE

Empirical Formula:

Ca_1.5Na_0.5Be_0.75Al_0.25Si₂O₅(OH)₂

IMA Status:

Approved IMA 1984

Locality:

Link to MinDat.org Location Data.

Synonym:

IMA1982-075

Search for Jeffreyite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Jeffreyite Crystallography

Axial Ratios:

a:b:c =1:1:2.712

Cell Dimensions:

a = 14.9, b = 14.9, c = 40.41, Z = 64; V = 8,971.42 Den(Calc)= 3.02

Crystal System:

Orthorhombic - DisphenoidalH-M Symbol (2 2 2) Space Group: C 222₁

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

By Intensity(I/I_o): 2.774(1), 2.993(0.9), 2.541(0.7),

Physical Properties of Jeffreyite

Cleavage:

[001] Perfect, [110] Perfect

Color:

Colorless.

Density:

2.99

Diaphaniety:

Transparent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Hardness:

5 - Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Jeffreyite

Gladstone-Dale:

CI meas= 0.077 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.086 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2107,KPDmeas= 0.2128,KC= 0.2306

Optical Data:

Biaxial (-), a=1.625, b=1.641, g=1.643, bire=0.0180, 2V(Calc)=38, 2V(Meas)=40.

Calculated Properties of Jeffreyite

Electron Density:

r_electron=2.99 gm/cc
note: r_Jeffreyite=2.99 gm/cc.

Fermion Index

Fermion Index = 0.03727
Boson Index = 0.96273

Photoelectric:

PE_Jeffreyite= 3.89 barns/electron
U=PE_Jeffreyite x r_electron= 11.64 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Jeffreyite is Not Radioactive

Jeffreyite Classification

Dana Class:

55.4.2.3 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.4)with cations in [8] and lower coordination

(55.4.2)Fresnoite group

55.4.2.1 Fresnoite Ba2TiSi2O8 P 4bm 4mm

55.4.2.2 Hardystonite Ca2ZnSi2O7 P 42₁m 4 2m

55.4.2.3 Jeffreyite (Ca,Na)2(Be,Al)Si2(O,OH)7 C 222₁ 2 2 2

55.4.2.4 Leucophanite (Na,Ca)2BeSi2(O,OH,F)7 P1 1

55.4.2.5 Meliphanite (Ca,Na)2Be[(Si,Al)2O6(F,OH)] I 4 4

55.4.2.6 Gugiaite Ca2BeSi2O7 P 42₁m 4 2m

Strunz Class:

VIII/C.02-60 VIII - Silicates

VIII/C - Sorosilicates, with [Si2O7]6-, without anions unfamiliar to tetraheders

VIII/C.02 - Melilite group

VIII/C.02-10 Akermanite Ca2MgSi2O7 P 42₁m 4 2m

VIII/C.02-14 Okayamalite! Ca2B2SiO7 P 42₁m 4 2m

VIII/C.02-15 Gehlenite Ca2Al(AlSi)O7 P 42₁m 4 2m

VIII/C.02-30 Gugiaite Ca2BeSi2O7 P 42₁m 4 2m

VIII/C.02-40 Hardystonite Ca2ZnSi2O7 P 42₁m 4 2m

VIII/C.02-50 Leucophanite (Na,Ca)2BeSi2(O,OH,F)7 P1 1

VIII/C.02-60 Jeffreyite (Ca,Na)2(Be,Al)Si2(O,OH)7 C 222₁ 2 2 2

VIII/C.02-70 Meliphanite (Ca,Na)2Be[(Si,Al)2O6(F,OH)] I 4 4

VIII/C.02-80 Barylite BaBe2Si2O7 Pn21a mm2

VIII/C.02-85 Clinobarylite! BaBe2Si2O7 Pmn2 2/m 2/m 2/m

VIII/C.02-90 Andremeyerite BaFe(Fe,Mn,Mg)Si2O7 P 2₁/c 2/m

Other Jeffreyite Information

References:

PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

Search for Jeffreyite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Jeffreyite :
AA Mineral Specimens
A-Rocks Auction
Adams Minerals
B and L Minerals
Dakota Matrix
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Minernet.it
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Jeffreyite Mineral Data :

Ask about Jeffreyite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Jeffreyite

(Ca,Na)2(Be,Al)Si2(O,OH)7
Dana No: 55.4.2.3 Strunz No: VIII/C.02-60
Locality:

Notes: