Parachrysotile Mineral Data

General Parachrysotile Information

Chemical Formula:

Mg3Si2O5(OH)4

Composition:

Molecular Weight = 277.11 gm

Magnesium 26.31 % Mg 43.63 % MgO

Silicon 20.27 % Si 43.36 % SiO₂

Hydrogen 1.45 % H 13.00 % H₂O

Oxygen 51.96 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg₃Si₂O₅(OH)₄

Environment:

Metamorphosed and hydrothermally-altered ultra-basic rocks. Parachrysotile (1956) is now regarded as polytype of chrysotile.

IMA Status:

Discredited IMA 2006 - Valid Species (Pre-IMA) 1951

Locality:

Asbestos, Quebec, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for the crystal structure and the relationship to chrysotile which is from the Greek chrysos - "gold" and tilos - "fiber."

Name Pronunciation:

Parachrysotile + Pronunciation

Synonym:

Amianthus

Asbestos

Chrysotile

Common asbestos

Parachrysotile Image

Images:

Parachrysotile

Comments: Asbestos fibers of greenish parachrysotile.
Location: Timmins, Ontario, Canada. Scale: 8x10 cm.
© Dave Barthelmy

Parachrysotile Crystallography

Axial Ratios:

a:b:c =0.576:1:1.5869

Cell Dimensions:

a = 5.3, b = 9.2, c = 14.6, Z = 4; V = 711.90 Den(Calc)= 2.59

Crystal System:

Orthorhombic Space Group: Unk

Physical Properties of Parachrysotile

Cleavage:

{???} Distinct

Color:

Green, Red, Yellow, White.

Density:

2.53 - 2.65, Average = 2.59

Diaphaneity:

Translucent to opaque

Fracture:

Fibrous - Thin, elongated fractures produced by crystal forms or intersecting cleavages (e.g. asbestos).

Habit:

Amorphous - No crystalline form or imitative shape.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Massive - Fibrous - Distinctly fibrous fine-grained forms.

Hardness:

2.5-3 - Finger Nail-Calcite

Luminescence:

Non-fluorescent.

Luster:

Silky

Streak:

white

Optical Properties of Parachrysotile

Gladstone-Dale:

CI meas= 0.027 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.027 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2158,KPDmeas= 0.2158,KC= 0.2217
Ncalc = 1.56 - 1.59

Optical Data:

Biaxial (-), a=1.545-1.569, b=1.546-1.569, g=1.553-1.571, bire=0.0020-0.0080, 2V(Calc)=0-42, 2V(Meas)=20-60. Dispersion relatively weak.

Calculated Properties of Parachrysotile

Electron Density:

Bulk Density (Electron Density)=2.62 gm/cc
note: Specific Gravity of Parachrysotile =2.59 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_{Parachrysotile}= 1.39 barns/electron
U=PE_{Parachrysotile} x rElectron Density= 3.64 barns/cc.

Radioactivity:

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

Parachrysotile Classification

Dana Class:

71.01.02d.03 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.01)with 1:1 layers

(71.01.02d)Serpentine group (Chrysotile subgroup)

71.01.02d.00 Chrysotile! Mg3Si2O5(OH)4 A2/m 2/m

71.01.02d.01 Clinochrysotile? Mg3Si2O5(OH)4 Cc, C 2/m Mono

71.01.02d.02 Orthochrysotile? Mg3Si2O5(OH)4 Unk Ortho

71.01.02d.03 Parachrysotile? Mg3Si2O5(OH)4 Unk Ortho

71.01.02d.04 Pecoraite Ni3Si2O5(OH)4 C 2/m 2/m

Strunz Class:

09.ED.15 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.ED -Phyllosilicates with kaolinite layers

09.ED.15 Clinochrysotile? Mg3Si2O5(OH)4 Cc, C 2/m Mono

09.ED.15 Berthierine (Fe,Fe,Al,Mg)2-3(Si,Al)2O5(OH)4 Cm m

09.ED.15 Brindleyite (Ni,Mg,Fe)2Al(SiAl)O5(OH)4 C 2 2

09.ED.15 Amesite Mg2Al(SiAl)O5(OH)4 C1 1

09.ED.15 Antigorite (Mg,Fe)3Si2O5(OH)4 Cm m

09.ED.15 Caryopilite (Mn,Mg,Zn,Fe)3(Si,As)2O510(OH,Cl)4 Cm or C 2/m Mono

09.ED.15 Fraipontite (Zn,Al)3(Si,Al)2O5(OH)4 Cm m

09.ED.15 Cronstedtite Fe2Fe(SiFe)O5(OH)4 P 3₁m 3m

09.ED.15 Chrysotile Mg3Si2O5(OH)4 A2/m 2/m

09.ED.15 Nepouite Ni3Si2O5(OH)4 Ccm21 mm2

09.ED.15 Greenalite (Fe,Fe)2-3Si2O5(OH)4 Unk Mono

09.ED.15 Kellyite (Mn,Mg,Al)3(Si,Al)2O5(OH)4 P 6₃ 6

09.ED.15 Maufite? (Mg,Ni)Al4Si3O13•4(H2O)(?) Mono ? Mono

09.ED.15 Lizardite Mg3Si2O5(OH)4 P1 1

09.ED.15 Orthochrysotile? Mg3Si2O5(OH)4 Unk Ortho

09.ED.15 Manandonite Li2Al4[(Si2AlB)O10](OH)8 C1 1

09.ED.15 Pecoraite Ni3Si2O5(OH)4 C 2/m 2/m

09.ED.15 Parachrysotile? Mg3Si2O5(OH)4 Unk Ortho

Other Parachrysotile Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Parachrysotile :
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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Parachrysotile

Mg3Si2O5(OH)4
Dana No: 71.01.02d.03 Strunz No: 09.ED.15
Locality:

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