Forsterite Mineral Data

Forsterite Mineral Data +

[Register] [Auction Rules] [Current Listing] [About Us] [Site Map]
e-Rocks.com, auction and sales venue for all rock and mineral enthusiasts
Our mission is to provide an online centre for Buyers and Sellers with reliable service and support
Brought to you by Thames Valley Minerals

General Forsterite Information

Chemical Formula:

Mg2SiO4

Composition:

Molecular Weight = 140.69 gm

Magnesium 34.55 % Mg 57.29 % MgO

Silicon 19.96 % Si 42.71 % SiO₂

Oxygen 45.49 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg₂(SiO₄)

Environment:

Ultramafic igneous rocks or dolomitic marbles.

IMA Status:

Valid Species (Pre-IMA) 1824

Locality:

Mte. Somma, Vesuvius, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for Johann Forster, German naturalist.

Synonym:

Chrysolite

ICSD 9334

Olivine

PDF 34-189

Peridot

Forsterite Image

Images:

Forsterite Olivine

Comments: Peridot (Forsterite) recrystallized at the base.
Location: Skardu, Nooristan, Pakistan. Scale: 2.5 x 2.7 cm.
© Fabre Minerals

Forsterite Crystallography

Axial Ratios:

a:b:c =0.4665:1:0.5866

Cell Dimensions:

a = 4.756, b = 10.195, c = 5.981, Z = 4; V = 290.00 Den(Calc)= 3.22

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pbnm

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

By Intensity(I/I_o): 2.458(1), 2.512(0.7), 3.883(0.7),

Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: [ 1 0 1] [ 1 0 0] [ 0 1 0] [ 1 1 0] [ 1 1 1] [ 0 0 1] [ 0 1 1]

Warning: this large pop-up is very compute intensive and may not work well with some computers.

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Birle J D , Gibbs G V , Moore P B , Smith J V , American Mineralogist , 53 (1968) p.807-824, Crystal structures of natural olivines

View Additional jPOWD Structure files for Forsterite
[1] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [2] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [3] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [4] [40] [41] [5] [6] [7] [8] [9]

Physical Properties of Forsterite

Cleavage:

[001] Good, [010] Distinct

Color:

Colorless, Green, Yellow, Yellow green, White.

Density:

3.21 - 3.33, Average = 3.27

Diaphaniety:

Transparent

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:

Tabular - Form dimensions are thin in one direction.

Hardness:

6-7 - Orthoclase-Quartz

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Forsterite

Gladstone-Dale:

CI meas= -0.051 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.068 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2172,KPDmeas= 0.2139,KC= 0.2034

Optical Data:

Biaxial (-), a=1.636-1.73, b=1.65-1.739, g=1.669-1.772, bire=0.0330-0.0420, 2V(Calc)=56-84, 2V(Meas)=74-90. Dispersion r > v or r < v.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Forsterite

Electron Density:

r_electron=3.25 gm/cc
note: r_Forsterite=3.27 gm/cc.

Fermion Index

Fermion Index = 0.04409
Boson Index = 0.95591

Photoelectric:

PE_Forsterite= 1.53 barns/electron
U=PE_Forsterite x r_electron= 4.98 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Forsterite is Not Radioactive

Forsterite Classification

Dana Class:

51.3.1.2 (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 2₁/b 2/m

Strunz Class:

VIII/A.04-10 VIII - Silicates

VIII/A - Nesosilicates with [SiO4]4-groups, cations of octahedral orientation [6]

VIII/A.04 - Olivine group

VIII/A.04-10 Forsterite Mg2SiO4 Pbnm 2/m 2/m 2/m

VIII/A.04-20 Fayalite Fe2SiO4 Pbnm 2/m 2/m 2/m

VIII/A.04-30 Tephroite Mn2SiO4 P nma 2/m 2/m 2/m

VIII/A.04-40 Liebenbergite (Ni,Mg)2SiO4 Pbnm 2/m 2/m 2/m

VIII/A.04-50 Laihunite FeFe2(SiO4)2 P 2₁/b 2/m

Other Forsterite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

Search for Forsterite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Forsterite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Forsterite Mineral Data :

Ask about Forsterite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Forsterite

Mg2SiO4
Dana No: 51.3.1.2 Strunz No: VIII/A.04-10
Locality:

Notes: