Akermanite Mineral Data

Akermanite Mineral Data +

[Mineral Auctions] [Register] [Current Auctions] [Log In] [www.danweinrich.com]
Dan Weinrich Auctions
Specializing In Live Weekly Auctions Of Top Quality Mineral Specimens
The Place To Find Great Specimens At Great Prices!

General Akermanite Information

Chemical Formula:

Ca2MgSi2O7

Composition:

Molecular Weight = 272.63 gm

Calcium 29.40 % Ca 41.14 % CaO

Magnesium 8.92 % Mg 14.78 % MgO

Silicon 20.60 % Si 44.08 % SiO₂

Oxygen 41.08 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂Mg(Si₂O₇)

Environment:

A product of contact metamorphism of siliceous limestones and dolostones, and in rocks of the sanidinite facies. Also, forms from alkalic magmas rich in calcium.

IMA Status:

Valid Species (Pre-IMA) 1884

Locality:

Occurrences are typically of intermediate series members; relatively pure examples have been found at Monte Somma and Vesuvius, Campania, and Monte Cavalluchio, Sacrofano, near Rome, L Link to MinDat.org Location Data.

Name Origin:

For Anders Richard Akerman (1837-1922), Swedish metallurgist.

Synonym:

ICSD 39924

PDF 35-592

Akermanite Image

Images:

Akermanite

Comments: White translucent crystals akermanite.
Location: Lago de Vico, Viterbo, Lazio, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Akermanite Crystallography

Axial Ratios:

a:c = 1:0.63903

Cell Dimensions:

a = 7.84, c = 5.01, Z = 2; V = 307.94 Den(Calc)= 2.94

Crystal System:

Tetragonal - ScalenohedralH-M Symbol (4 2m) Space Group: P 42₁m

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

By Intensity(I/I_o): 2.87(1), 1.76(0.3), 3.09(0.3),

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

Swainson I P , Dove M T , Schmahl W W , Putnis A , Physics and Chemistry of Minerals , 19 (1992) p.185-195, Neutron powder diffraction study of the akermanite-gehlenite, solid solution series, Sample: 50% Ak

View Additional jPOWD Structure files for Akermanite
[1] [10] [11] [12] [13] [14] [15] [16] [17] [18] [2] [3] [4] [5] [6] [7] [8] [9]

Physical Properties of Akermanite

Cleavage:

[001] Distinct, [110] Indistinct

Color:

Colorless, Grayish, Green, Brown.

Density:

2.944

Diaphaniety:

Transparent to Translucent

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous - Resinous

Streak:

white

Optical Properties of Akermanite

Gladstone-Dale:

CI meas= -0.04 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.042 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2163,KPDmeas= 0.216,KC= 0.2076

Optical Data:

Uniaxial (+), w=1.632, e=1.64, bire=0.0080.

Calculated Properties of Akermanite

Electron Density:

r_electron=2.94 gm/cc
note: r_Akermanite=2.94 gm/cc.

Fermion Index

Fermion Index = 0.01913
Boson Index = 0.98087

Photoelectric:

PE_Akermanite= 4.59 barns/electron
U=PE_Akermanite x r_electron= 13.48 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Akermanite is Not Radioactive

Akermanite Classification

Dana Class:

55.4.1.1 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.4)with cations in [8] and lower coordination

(55.4.1)Melilite group

55.4.1.1 Akermanite Ca2MgSi2O7 P 42₁m 4 2m

55.4.1.2 Gehlenite Ca2Al(AlSi)O7 P 42₁m 4 2m

55.4.1.3 Melilite (Ca,Na)2(Al,Mg,Fe)(Si,Al)2O7 P 42₁m 4 2m

55.4.1.4 Okayamalite! Ca2B2SiO7 P 42₁m 4 2m

Strunz Class:

VIII/C.02-10 VIII - Silicates

VIII/C - Sorosilicates, with [Si2O7]6-, without anions unfamiliar to tetraheders

VIII/C.02 - Melilite group

VIII/C.02-10 Akermanite Ca2MgSi2O7 P 42₁m 4 2m

VIII/C.02-14 Okayamalite! Ca2B2SiO7 P 42₁m 4 2m

VIII/C.02-15 Gehlenite Ca2Al(AlSi)O7 P 42₁m 4 2m

VIII/C.02-30 Gugiaite Ca2BeSi2O7 P 42₁m 4 2m

VIII/C.02-40 Hardystonite Ca2ZnSi2O7 P 42₁m 4 2m

VIII/C.02-50 Leucophanite (Na,Ca)2BeSi2(O,OH,F)7 P1 1

VIII/C.02-60 Jeffreyite (Ca,Na)2(Be,Al)Si2(O,OH)7 C 222₁ 2 2 2

VIII/C.02-70 Meliphanite (Ca,Na)2Be[(Si,Al)2O6(F,OH)] I 4 4

VIII/C.02-80 Barylite BaBe2Si2O7 Pn21a mm2

VIII/C.02-85 Clinobarylite! BaBe2Si2O7 Pmn2 2/m 2/m 2/m

VIII/C.02-90 Andremeyerite BaFe(Fe,Mn,Mg)Si2O7 P 2₁/c 2/m

Other Akermanite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

Search for Akermanite using:

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

Visit our Advertisers for Akermanite :
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 Akermanite Mineral Data :

Ask about Akermanite 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 Akermanite Specimen Label here :

Akermanite

Ca2MgSi2O7
Dana No: 55.4.1.1 Strunz No: VIII/C.02-10
Locality:

Notes: