Lonsdaleite Mineral Data

General Lonsdaleite Information

Chemical Formula:

Composition:

Molecular Weight = 12.01 gm

Carbon 100.00 % C

______

100.00 %

Empirical Formula:

Environment:

Associated with diamond in the Canyon Diablo, Goalpara, and Allan Hills 77283 meteorites. Also in diamond-bearing placers.

IMA Status:

Approved IMA 1967

Locality:

Tunguska impact site, Russia. Other world-wide impact sites. Link to MinDat.org Location Data.

Name Origin:

Named for Kathleen Lonsdale (1903-1971), English crystallographer.

Name Pronunciation:

Lonsdaleite + Pronunciation

Synonym:

ICSD 27422

PDF 19-268

Lonsdaleite Image

Images:

Lonsdaleite

Comments: a) A Reflected light photograph of lonsdaleite and unidentified polymorph (New Phase) with lead comtamination. b) synchrotron X-ray diffraction, imaging and X-ray fluorescence fine-scale mapping of the different phases. (ESRF 2003 highlights).
Location: Shocked gneisses from the Popigai Crater, Russia. Scale: See Image.
© Eur. Sync. Rad. Fac.

Lonsdaleite Crystallography

Axial Ratios:

a:c = 1:1.63492

Cell Dimensions:

a = 2.52, c = 4.12, Z = 4; V = 22.66 Den(Calc)= 3.52

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

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

By Intensity(I/I_o): 2.06(1), 2.19(1), 1.26(0.75),

Physical Properties of Lonsdaleite

Cleavage:

{???} Perfect

Color:

Brownish black, Light brownish yellow.

Density:

3.3 - 3.52, Average = 3.41

Diaphaneity:

Translucent to Opaque

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

7-8

Luster:

Adamantine

Streak:

brownish yellow

Optical Properties of Lonsdaleite

Optical Data:

Uniaxial (+/-), a=2.404, b=2.404, bire=0.0000.

Calculated Properties of Lonsdaleite

Electron Density:

Bulk Density (Electron Density)=3.52 gm/cc
note: Specific Gravity of Lonsdaleite =3.52 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Lonsdaleite= 0.16 barns/electron
U=PE_Lonsdaleite x rElectron Density= 0.56 barns/cc.

Radioactivity:

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

Lonsdaleite Classification

Dana Class:

01.03.06.03 (01)Native Elements

(01.03)with semi-metallic and non-metallic elements

(01.03.06)Carbon Polymorph group

01.03.06.01 Diamond C F d3m 4/m 3 2/m

01.03.06.02 Graphite C P 6₃/mmc 6/m 2/m 2/m

01.03.06.03 Lonsdaleite C P 6₃/mmc 6/m 2/m 2/m

01.03.06.04 Chaoite C P 6/mmm 6/m 2/m 2/m

01.03.06.05 Fullerite! C60 pseudo-CUBIC 4/m 2/m 2/m

Strunz Class:

01.CB.10b 01 - ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)

01.C - Metalloids and Nonmetals

01.CB -Carbon-silicon family

01.CB.10b Lonsdaleite C P 6₃/mmc 6/m 2/m 2/m

Other Lonsdaleite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic1)

See Also:

Links to other databases for Lonsdaleite :
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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Lonsdaleite

C
Dana No: 01.03.06.03 Strunz No: 01.CB.10b
Locality:

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