Stevensite Mineral Data

General Stevensite Information

Chemical Formula:

(Ca0.5,Na)0.33(Mg,Fe++)3Si4O10(OH)2•n(H2O)

Composition:

Molecular Weight = 471.23 gm

Sodium 1.61 % Na 2.17 % Na₂O

Calcium 1.28 % Ca 1.79 % CaO

Magnesium 14.44 % Mg 23.95 % MgO

Iron 2.37 % Fe 3.05 % FeO

Silicon 23.84 % Si 51.00 % SiO₂

Hydrogen 2.14 % H 19.12 % H₂O

Oxygen 54.32 % O

______ ______

100.00 % 101.07 % = TOTAL OXIDE

Empirical Formula:

Ca_0.15Na_0.33Mg_2.8Fe²⁺_0.2Si₄O₁₀(OH)₂•4(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1873

Locality:

Railway tunnel, Bergen Hill, Hudson County, New Jersey, USA. Link to MinDat.org Location Data.

Name Origin:

Named for E. A. Stevens, founder of Stevens Institute of Technology, Hoboken, New Jersey, USA.

Name Pronunciation:

Stevensite + Pronunciation

Synonym:

Cerolite

Jurupaite

Kerolite

Stevensite Image

Images:

Stevensite

Comments: Granular massive stevensite.
Location: Langban, Varmland, Sweden. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Stevensite Crystallography

Axial Ratios:

a:b:c =0.5775:1:1.6798

Cell Dimensions:

a = 5.26, b = 9.108, c = 15.3, Z = 2; beta = 90° V = 732.99 Den(Calc)= 2.13

Crystal System:

Monoclinic Space Group: Unk (ORTH ?)

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

By Intensity(I/I_o): 15.5(1), 4.53(0.35), 1.518(0.15),

Physical Properties of Stevensite

Cleavage:

{001} Perfect

Color:

Beige white, Yellow brown, Pink.

Density:

2.15 - 2.75, Average = 2.45

Diaphaneity:

Translucent

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

4 - Fluorite

Luminescence:

Non-fluorescent.

Luster:

Resinous

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Stevensite

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.137 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2645,KPDmeas= 0.2299,KC= 0.2326
Ncalc = 1.5 - 1.64

Optical Data:

Biaxial (+), a=1.56, b=1.56, g=1.57, bire=0.0100

Calculated Properties of Stevensite

Electron Density:

Bulk Density (Electron Density)=2.49 gm/cc
note: Specific Gravity of Stevensite =2.45 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Stevensite= 2.14 barns/electron
U=PE_Stevensite x rElectron Density= 5.32 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Stevensite is Not Radioactive

Stevensite Classification

Dana Class:

71.03.01b.06 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.03)with 2:1 clays

(71.03.01b)Smectite group (Trioctahedral Smectites)

71.03.01b.01 Sobotkite? (K,Ca0.5)0.33(Mg,Al)3(Si3Al)O10(OH)2•1-5(H2O) Unk. Mono

71.03.01b.02 Saponite (Ca/2,Na)0,3(Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

71.03.01b.02a Ferrosaponite! Ca0.3(Fe,Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C? Mono

71.03.01b.03 Sauconite Na0,3Zn3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

71.03.01b.04 Hectorite Na0,3(Mg,Li)3Si4O10(OH)2 C 2/m 2/m

71.03.01b.05 Pimelite? Ni3Si4O10(OH)2•4(H2O) Unk. Hex

71.03.01b.06 Stevensite (Ca0.5,Na)0.33(Mg,Fe)3Si4O10(OH)2•n(H2O) Unk (ORTH ?) Mono

71.03.01b.07 Yakhontovite (Ca,K)0.5(Cu,Fe,Mg)2Si4O10(OH)2•3(H2O) C 2/m 2/m

71.03.01b.08 Zincsilite Zn3Si4O10(OH)2•4(H2O)(?) C 2/m ? 2/m

Strunz Class:

09.EC.45 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.45 Griffithite* 4(Mg,Fe,Ca)O.(Al,Fe)2O3.5SiO2•7(H2O) Mono

09.EC.45 Hectorite Na0,3(Mg,Li)3Si4O10(OH)2 C 2/m 2/m

09.EC.45 Swinefordite (Li,Ca0.5,Na)0.72(Li,Al,Mg)2.66(Si,Al)4O10(OH,F)2•2(H2O) C 2/m (MON or ORTH) 2/m

09.EC.45 Zincsilite Zn3Si4O10(OH)2•4(H2O)(?) C 2/m ? 2/m

09.EC.45 Saponite (Ca/2,Na)0,3(Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

09.EC.45 Sauconite Na0,3Zn3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

09.EC.45 Spadaite MgSiO2(OH)2•(H2O)(?) Ortho

09.EC.45 Sobotkite? (K,Ca0.5)0.33(Mg,Al)3(Si3Al)O10(OH)2•1-5(H2O) Unk. Mono

09.EC.45 Stevensite (Ca0.5,Na)0.33(Mg,Fe)3Si4O10(OH)2•n(H2O) Unk (ORTH ?) Mono

09.EC.45 Ferrosaponite! Ca0.3(Fe,Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C? Mono

Other Stevensite Information

References:

PHYS. PROP.(Dana8) OPTIC PROP.(Dana)

See Also:

Links to other databases for Stevensite :
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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Stevensite

(Ca0.5,Na)0.33(Mg,Fe++)3Si4O10(OH)2•n(H2O)
Dana No: 71.03.01b.06 Strunz No: 09.EC.45
Locality:

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