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 % H2 O
Oxygen 51.96 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg3 Si2 O5 (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:
PEParachrysotile = 1.39 barns/electronU=PEParachrysotile x r Electron 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 31 m 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
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