Ludwigite Mineral Data

General Ludwigite Information

Chemical Formula:

Mg2Fe+++BO5

Composition:

Molecular Weight = 195.26 gm

Magnesium 24.89 % Mg 41.28 % MgO

Iron 28.60 % Fe 40.89 % Fe₂O₃

Boron 5.54 % B 17.83 % B₂O₃

Oxygen 40.97 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg₂Fe³⁺BO₅

Environment:

Typically formed in a magnesian iron skarn and contact metamorphic deposits. Forms a series with vonsenite.

IMA Status:

Valid Species (Pre-IMA) 1874

Locality:

Ocna de Fier (Vask�, Mor�vica, Eisenstein), Banat, Romania Link to MinDat.org Location Data.

Name Origin:

Named after the Austrian chemist, Ernst Ludwig (1842-1915).

Name Pronunciation:

Ludwigite + Pronunciation

Synonym:

ICSD 65435

Magnesioludwighite

PDF 46-1290

Ludwigite Image

Images:

Ludwigite

Comments: Limonitic matrix with blue crystals of ludwigite.
Location: Simms Pass, Lemhi County, Idaho, USA. Scale: Crystal size 9 mm.
© John Veevaert

Images:

Chestermanite Ludwigite

Comments: Black capillary crystals of ludwigite with green inclusions of chestermanite in impure marble.
Location: Near Potter Pass, Fresno County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Ludwigite

Comments: Bright black, radial fibrous aggregates of ludwigite.
Location: Brosso mine, Piemonte, Italy. Scale: Sample size 4x3 cm.
© Sandro Maggia/Minernet.it

Ludwigite Crystallography

Axial Ratios:

a:b:c =0.7553:1:0.2487

Cell Dimensions:

a = 9.26, b = 12.26, c = 3.05, Z = 4; V = 346.26 Den(Calc)= 3.75

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbam

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

By Intensity(I/I_o): 5.12(1), 2.515(0.7), 2.547(0.7),

Physical Properties of Ludwigite

Cleavage:

{001} Perfect

Color:

Dark green, Black, Black green.

Density:

3.7 - 4, Average = 3.85

Diaphaneity:

Opaque to subtranslucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Massive - Fibrous - Distinctly fibrous fine-grained forms.

Habit:

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

Hardness:

5.5 - Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Silky

Streak:

greenish black

Optical Properties of Ludwigite

Gladstone-Dale:

CI meas= 0.062 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.037 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2404,KPDmeas= 0.2342,KC= 0.2497
Ncalc = 1.92 - 2

Optical Data:

Biaxial (+), a=1.83-1.85, b=1.83-1.9, g=1.97-2.03, bire=0.1400-0.1800, 2V(Calc)=0-68, 2V(Meas)=Small. Dispersion r >> v extreme.

Pleochroism (x):

dark green.

Pleochroism (y):

dark green.

Pleochroism (z):

dark reddish brown.

RL Anisotrophism:

Strong, yellowish brown to bluish violet gray.

RL Bireflectance:

Pinkish gray to dark greenish gray.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Ludwigite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	10.10	13.80
420 nm	9.70	13.20
440 nm	9.30	12.60
460 nm	9.00	12.10
480 nm	8.70	11.80
500 nm	8.50	11.50
520 nm	8.20	11.30
540 nm	8.10	11.20
560 nm	7.90	11.00
580 nm	7.80	10.90
600 nm	7.60	10.80
620 nm	7.50	10.80
640 nm	7.40	10.80
660 nm	7.30	10.80
680 nm	7.20	10.80
700 nm	7.20	10.90

**Calculated Relative Intensity Colors of Ludwigite in Air**
Relative Intensity	0%	100%	200%	300%	400%	500%	600%	700%	800%	900%	1000%
R₁
R₂

Calculated Properties of Ludwigite

Electron Density:

Bulk Density (Electron Density)=3.65 gm/cc
note: Specific Gravity of Ludwigite =3.75 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_Ludwigite= 9.17 barns/electron
U=PE_Ludwigite x rElectron Density= 33.46 barns/cc.

Radioactivity:

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

Ludwigite Classification

Dana Class:

24.02.01.01 (24)Borates - Anhydrous

(24.02)where (A)2 BO2 [XO3]

(24.02.01)Ludwigite Group (Space Group: Pbam)

24.02.01.01 Ludwigite Mg2FeBO5 Pbam 2/m 2/m 2/m

24.02.01.02 Vonsenite Fe2FeBO5 Pbam 2/m 2/m 2/m

24.02.01.03 Azoproite (Mg,Fe)2(Fe,Ti,Mg)BO5 Pbam 2/m 2/m 2/m

24.02.01.04 Bonaccordite Ni2FeBO5 Pbam 2/m 2/m 2/m

24.02.01.05 Chestermanite Mg2(Fe,Mg,Al,Sb)BO3O2 Pbam 2/m 2/m 2/m

24.02.01.06 Fredrikssonite Mg2(Mn,Fe)O2(BO3) Pbam 2/m 2/m 2/m

Strunz Class:

06.AB.30 06 - BORATES

06.A - Monoborates

06.AB -BO3, with additional anions; 1(D) + OH, etc.

06.AB.30 Azoproite (Mg,Fe)2(Fe,Ti,Mg)BO5 Pbam 2/m 2/m 2/m

06.AB.30 Bonaccordite Ni2FeBO5 Pbam 2/m 2/m 2/m

06.AB.30 Fredrikssonite Mg2(Mn,Fe)O2(BO3) Pbam 2/m 2/m 2/m

06.AB.30 Ludwigite Mg2FeBO5 Pbam 2/m 2/m 2/m

06.AB.30 Vonsenite Fe2FeBO5 Pbam 2/m 2/m 2/m

Other Ludwigite Information

References:

NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic5)

See Also:

Links to other databases for Ludwigite :
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 - Scandinavian mineral gallery
16 - WWW-MINCRYST

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

Ludwigite

Mg2Fe+++BO5
Dana No: 24.02.01.01 Strunz No: 06.AB.30
Locality:

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