Chondrodite Mineral Data

General Chondrodite Information

Chemical Formula:

(Mg,Fe++)5(SiO4)2(F,OH)2

Composition:

Molecular Weight = 382.12 gm

Magnesium 23.85 % Mg 39.55 % MgO

Iron 18.27 % Fe 23.50 % FeO

Silicon 14.70 % Si 31.45 % SiO₂

Hydrogen 0.13 % H 1.18 % H₂O

Oxygen 35.59 % O

Fluorine 7.46 % F 7.46 % F

- % F -3.14 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_3.75Fe²⁺_1.25(SiO₄)₂F_1.5(OH)_0.5

Environment:

Contact metamorphic rocks.

IMA Status:

Valid Species (Pre-IMA) 1817

Locality:

Wunsiedel and Passau, Germany. Link to MinDat.org Location Data.

Name Origin:

From the Greek chondros - "grain."

Name Pronunciation:

Chondrodite + Pronunciation

Synonym:

Fluosiderite - F-rich chondrodite

ICSD 15180

PDF 12-527

Chondrodite Image

Images:

Chondrodite

Comments: Lustrous and semi-transparent crystal of reddish brown chondrodite 1 cm in size with magnetite and muscovite.
Location: Palabora mine, Loolekop, Phalaborwa, Limpopo Province, South Africa. Scale: 4 x 2.6 x 2.4 cm.
© John Betts - Fine Minerals

Images:

Warwickite Chondrodite

Comments: Black crystalline warwickite with tan chondrodite in white marble.
Location: Amity, near Warwick, Orange County, New York, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Chondrodite Crystallography

Axial Ratios:

a:b:c =1.6638:1:2.1712

Cell Dimensions:

a = 7.87, b = 4.73, c = 10.27, Z = 2; beta = 109.033° V = 361.40 Den(Calc)= 3.51

Crystal System:

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

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

By Intensity(I/I_o): 2.252(1), 2.272(1), 1.737(0.95),

Physical Properties of Chondrodite

Cleavage:

{100} Good

Color:

Yellow, Orange, Brownish white, Reddish white, Greenish white.

Density:

3.1 - 3.2, Average = 3.15

Diaphaneity:

Transparent to translucent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Crystalline - Fine - Occurs as well-formed fine sized crystals.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

6-6.5 - Orthoclase-Pyrite

Luminescence:

Fluorescent, Short UV=orange yellow, Long UV=orange.

Luster:

Vitreous - Greasy

Streak:

gray

Optical Properties of Chondrodite

Gladstone-Dale:

CI meas= -0.021 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.084 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1798,KPDmeas= 0.2003,KC= 0.1962
Ncalc = 1.61 - 1.69

Optical Data:

Biaxial (+), a=1.592-1.643, b=1.602-1.655, g=1.619-1.675, bire=0.0270-0.0320, 2V(Calc)=76-78, 2V(Meas)=64-90. Dispersion weak to moderate, r > v.

Pleochroism (x):

yellowish brown, deep chrome yellow, reddish brown, or brownish yellow.

Pleochroism (y):

pale yellowish brown, yellow, pale reddish brown, or yellowish green.

Calculated Properties of Chondrodite

Electron Density:

Bulk Density (Electron Density)=3.09 gm/cc
note: Specific Gravity of Chondrodite =3.15 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Chondrodite= 6.55 barns/electron
U=PE_Chondrodite x rElectron Density= 20.25 barns/cc.

Radioactivity:

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

Chondrodite Classification

Dana Class:

52.03.02b.02 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.03)with cations in [6] coordination only

(52.03.02b)Humite group (Chondrodite series)

52.03.02b.01 Alleghanyite Mn5(SiO4)2(OH)2 P 2₁/a 2/m

52.03.02b.02 Chondrodite (Mg,Fe)5(SiO4)2(F,OH)2 P 2₁/c 2/m

52.03.02b.03 Reinhardbraunsite Ca5(SiO4)2(OH,F)2 P 2₁/a 2/m

52.03.02b.04 Ribbeite (Mn,Mg)5(SiO4)2(OH)2 P nma 2/m 2/m 2/m

52.03.02b.05 Kumtyubeite! Ca5(SiO4)2F2 P 2₁/a 2/m

Strunz Class:

09.AF.45 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AF -Nesosilicates with additional anions;

09.AF.45 Alleghanyite Mn5(SiO4)2(OH)2 P 2₁/a 2/m

09.AF.45 Chondrodite (Mg,Fe)5(SiO4)2(F,OH)2 P 2₁/c 2/m

09.AF.45 Reinhardbraunsite Ca5(SiO4)2(OH,F)2 P 2₁/a 2/m

09.AF.45 Kumtyubeite! Ca5(SiO4)2F2 P 2₁/a 2/m

Other Chondrodite Information

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Chondrodite

(Mg,Fe++)5(SiO4)2(F,OH)2
Dana No: 52.03.02b.02 Strunz No: 09.AF.45
Locality:

Notes:

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