Esperite Mineral Data

General Esperite Information

Chemical Formula:

PbCa3Zn4(SiO4)4

Composition:

Molecular Weight = 957.33 gm

Calcium 12.56 % Ca 17.57 % CaO

Zinc 27.32 % Zn 34.01 % ZnO

Silicon 11.73 % Si 25.11 % SiO₂

Lead 21.64 % Pb 23.31 % PbO

Oxygen 26.74 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

PbCa₃Zn₄(SiO₄)₄

Environment:

Metamorphosed zinc deposits associated with larsenite.

IMA Status:

Approved IMA 1965

Locality:

Franklin, Sussex Co., New Jersey, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Esper Signius Larsen, Jr. (1879-1961), petrologist and Professor of Geology, Harvard University.

Name Pronunciation:

Esperite

Synonym:

Calcium larsenite

Esperite Image

Images:

Esperite Hardystonite Franklinite

Comments: Pale brown porcelaneous esperite with pinkish gray hardystonite and black franklinite.
Location: Franklin, Sussex County, New Jersey. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Esperite Crystallography

Axial Ratios:

a:b:c =2.1318:1:3.6904

Cell Dimensions:

a = 17.63, b = 8.27, c = 30.52, Z = 12; beta = 90° V = 4,449.82 Den(Calc)= 4.29

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: B21/m

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

By Intensity(I/I_o): 3.017(1), 2.534(0.75), 7.62(0.45),

Physical Properties of Esperite

Cleavage:

{???} Indistinct

Color:

White.

Density:

4.421

Diaphaneity:

Subtranslucent to opaque

Fracture:

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

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

5 - Apatite

Luminescence:

Fluorescent, Short UV=bright lemon yellow.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Esperite

Gladstone-Dale:

CI meas= 0 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.031 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1792,KPDmeas= 0.1739,KC= 0.1739
Ncalc = 1.75 - 1.77

Optical Data:

Biaxial (-), a=1.762, b=1.77, g=1.774, bire=0.0120

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Esperite

Electron Density:

Bulk Density (Electron Density)=4.12 gm/cc
note: Specific Gravity of Esperite =4.42 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_Esperite= 372.72 barns/electron
U=PE_Esperite x rElectron Density=1,535.36 barns/cc.

Radioactivity:

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

Esperite Classification

Dana Class:

51.02.01.03 (51)Nesosilicate Insular SiO4 Groups Only

(51.02)with cations in [4] as well as >[4]

(51.02.01)Trimerite group

51.02.01.01 Trimerite CaMn2Be3(SiO4)3 P 2₁/c 2/m

51.02.01.02 Larsenite PbZnSiO4 Pnam 2/m 2/m 2/m

51.02.01.03 Esperite PbCa3Zn4(SiO4)4 B21/m 2/m

Strunz Class:

09.AB.15 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AB -Nesosilicates without additional anions;

09.AB.15 Esperite PbCa3Zn4(SiO4)4 B21/m 2/m

Other Esperite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Esperite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - Franklin Minerals(Dunn)
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info

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

Esperite

PbCa3Zn4(SiO4)4
Dana No: 51.02.01.03 Strunz No: 09.AB.15
Locality:

Notes:

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