Mineraller ve özellikleri Olivin General Olivine Information Chemical Formula: (Mg,Fe)2SiO4 Composition: Molecular Weight = 153.31 gm Magnesium 25.37 % Mg 42.06 % MgO Iron 14.57 % Fe 18.75 % FeO Silicon 18.32 % Si 39.19 % SiO 2 Oxygen 41.74 % O ______ ______ 100.00 % 100.00 % = TOTAL OXIDE Empirical Formula: Mg 1.6Fe 2+ 0.4(SiO 4) Environment: Basic and ultra basic igneous rocks. IMA Status: Not Approved IMA Locality: Common world wide occurrence. Link to MinDat.org Location Data. Name Origin: Named after the green color. Synonym: Chrysolite - light yellowish green Peridot Olivine Crystallography Axial Ratios: a:b:c =0.4663:1:0.6146 Cell Dimensions: a = 4.78, b = 10.25, c = 6.3, Z = 4; V = 308.67 Den(Calc)= 3.30 Crystal System: Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pbnm Physical Properties of Olivine Cleavage: [001] Good, [010] Distinct Color: Yellowish green, Olive green, Greenish black, Reddish brown. Density: 3.27 - 3.37, Average = 3.32 Diaphaniety: Transparent to translucent Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments. Habit: Massive - Granular - Common texture observed in granite and other igneous rock. Hardness: 6.5-7 - Pyrite-Quartz Luminescence: Non-fluorescent. Luster: Vitreous (Glassy) Streak: white Optical Properties of Olivine Gladstone-Dale: CI meas= 0.01 (Superior) - where the CI = (1- KPDmeas/KC) CI calc= 0.004 (Superior) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2,KPDmeas= 0.1988,KC= 0.2009 Optical Data: Biaxial (+), a=1.63-1.65, b=1.65-1.67, g=1.67-1.69, bire=0.0400, 2V(Calc)=88, 2V(Meas)=46-98. Dispersion relatively weak. Olivine Classification Dana Class: 51.3.1.0 (51)Nesosilicate Insular SiO4 Groups Only (51.3)with all cations in octahedral [6] coordination (51.3.1)Olivine group 51.3.1.0 Olivine * (Mg,Fe)2SiO4 Pbnm 2/m 2/m 2/m 51.3.1.1 Fayalite Fe2SiO4 Pbnm 2/m 2/m 2/m 51.3.1.2 Forsterite Mg2SiO4 Pbnm 2/m 2/m 2/m 51.3.1.3 Liebenbergite (Ni,Mg)2SiO4 Pbnm 2/m 2/m 2/m 51.3.1.4 Tephroite Mn2SiO4 P nma 2/m 2/m 2/m 51.3.1.5 Laihunite FeFe2(SiO4)2 P 2 1/b 2/m Strunz Class: VIII/A.04-00 VIII - Silicates VIII/A - Nesosilicates with [SiO4]4-groups, cations of octahedral orientation [6] VIII/A.04 - Olivine group