Spadaite Mineral Data

General Spadaite Information

Chemical Formula:

MgSiO2(OH)2•(H2O) (?)

Composition:

Molecular Weight = 136.42 gm

Magnesium 17.82 % Mg 29.54 % MgO

Silicon 20.59 % Si 44.04 % SiO₂

Hydrogen 2.96 % H 26.41 % H₂O

Oxygen 58.64 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg(SiO₂)(OH)₂•(H₂O)

Environment:

Found replacing tactite minerals.

IMA Status:

Valid Species (Pre-IMA) 1843

Locality:

Capo di Bove, near Rome, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for Lavino Spada (De Medici) (1801-1863), Italian politicioan and amateur mineralogist.

Spadaite Image

Images:

Spadaite

Comments: Tan mottled silky fibrous spadaite, slightly flexible coatings.
Location: Palos Verdes Hills, Los Angeles County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Spadaite Crystallography

Crystal System:

Orthorhombic

Physical Properties of Spadaite

Cleavage:

None

Color:

Colorless, Cream, Pinkish.

Density:

2.2

Diaphaneity:

Translucent to subtranslucent

Habit:

Amorphous - No crystalline form or imitative shape.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

2.5 - Finger Nail

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Dull

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Spadaite

Gladstone-Dale:

CI meas= -0.004 (Superior) - where the CI = (1-KPDmeas/KC)
KPDmeas= 0.2414,KC= 0.2405
Ncalc = 1.53

Optical Data:

Biaxial (+), a=1.521, b=1.525-1.53, g=1.545, bire=0.0240

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Spadaite

Electron Density:

Bulk Density (Electron Density)=2.26 gm/cc
note: Specific Gravity of Spadaite =2.20 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Spadaite= 1.25 barns/electron
U=PE_Spadaite x rElectron Density= 2.83 barns/cc.

Radioactivity:

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

Spadaite Classification

Dana Class:

78.07.14.01 (78)Unclassified silicates

(78.07)wholly unclassified silicates

(78.07.14)Dana Group

78.07.14.01 Spadaite MgSiO2(OH)2•(H2O)(?) Ortho

78.07.14.02 Chesnokovite! Na2[SiO2(OH)2]•8H2O I bca 2/m 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 Spadaite Information

References:

NAME( Dana8) PHYS. PROP.(Dana) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Spadaite :
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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Print or Cut-and-Paste your Spadaite Specimen Label here :

Spadaite

MgSiO2(OH)2•(H2O) (?)
Dana No: 78.07.14.01 Strunz No: 09.EC.45
Locality:

Notes: