Foshagite Mineral Data

General Foshagite Information

Chemical Formula:

Ca4Si3O9(OH)2

Composition:

Molecular Weight = 422.58 gm

Calcium 37.94 % Ca 53.08 % CaO

Silicon 19.94 % Si 42.66 % SiO₂

Hydrogen 0.48 % H 4.26 % H₂O

Oxygen 41.65 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₄Si₃O₉(OH)₂

Environment:

Metamorphosed limestone.

IMA Status:

Valid Species (Pre-IMA) 1925

Locality:

Crestmore quarry, 5 miles NW of Riverside, Riverside Co. California. Link to MinDat.org Location Data.

Name Origin:

Named for William Fredrick Foshag (1894-1956), mineralogist and former curator at U. S. National Museum.

Name Pronunciation:

Foshagite + Pronunciation

Synonym:

ICSD 25818

PDF 29-377

Foshagite Image

Images:

Foshagite

Comments: Tan to gray fibrous to columnar aggregate of foshagite.
Location: Crestmore Quarry, Riverside County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Foshagite Crystallography

Axial Ratios:

a:b:c =2.8423:1:1.9213

Cell Dimensions:

a = 10.406, b = 3.661, c = 7.034, Z = 1; beta = 107.07° V = 256.16 Den(Calc)= 2.74

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/m

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

By Intensity(I/I_o): 2.953(1), 3.36(0.25), 4.96(0.25),

Physical Properties of Foshagite

Cleavage:

{001} Distinct

Color:

Snow white.

Density:

2.36

Diaphaneity:

Translucent

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Fibrous - Crystals made up of fibers.

Luminescence:

Fluorescent, Short UV=yellowish to blue white, Long UV=butter yellow.

Luster:

Silky

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Foshagite

Gladstone-Dale:

CI meas= -0.175 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.012 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2173,KPDmeas= 0.2523,KC= 0.2147
Ncalc = 1.51 - 1.59

Optical Data:

Biaxial (+), a=1.594, b=1.594, g=1.598, bire=0.0040

Calculated Properties of Foshagite

Electron Density:

Bulk Density (Electron Density)=2.75 gm/cc
note: Specific Gravity of Foshagite =2.74 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Foshagite= 5.40 barns/electron
U=PE_Foshagite x rElectron Density= 14.85 barns/cc.

Radioactivity:

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

Foshagite Classification

Dana Class:

65.02.02.01 (65)Inosilicate Single-Width Unbranched Chains, W=1

(65.02)with chains P=3

(65.02.02)Dana Group

65.02.02.01 Foshagite Ca4Si3O9(OH)2 P 2₁/m 2/m

Strunz Class:

09.DG.15 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DG -Inosilicates with 3-periodic single and multiple chains

09.DG.15 Foshagite Ca4Si3O9(OH)2 P 2₁/m 2/m

Other Foshagite Information

References:

NAME( Dana8) PHYS. PROP.(Collectors Book of Fluorescent Minerals) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Foshagite :
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
15 - WWW-MINCRYST

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

Foshagite

Ca4Si3O9(OH)2
Dana No: 65.02.02.01 Strunz No: 09.DG.15
Locality:

Notes:

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