Magnesiocummingtonite Mineral Data

[Content and History] [Recent Issues] [Back Issues] [Subscriptions] [Contacts]
See Also: [Diamond Crystals] [Excalibur Minerals] [Hudson Institute] [Minerals on CDROM]
Mineral News was founded some twenty years ago and has developed a following of
avid mineral collectors seeking timely information about new finds and other items
of interest to the collector community. Articles are solicited from collector and scientific authors.

General Magnesiocummingtonite Information

Chemical Formula:

(Mg,Fe++)7Si8O22(OH)2

Composition:

Molecular Weight = 836.02 gm

Magnesium 15.26 % Mg 25.31 % MgO

Iron 11.69 % Fe 15.04 % FeO

Silicon 26.88 % Si 57.50 % SiO₂

Hydrogen 0.24 % H 2.15 % H₂O

Oxygen 45.93 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_5.25Fe²⁺_1.75Si₈O₂₂(OH)₂

IMA Status:

Approved IMA 1969

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named as per current IMA amphibole nomenclature (Burke and Leake 2004; Can. Mineral., 42, 1881-1883). Dashkensanite (1936) was revalidated and renamed 2005.

Synonym:

ICSD 41925

PDF 17-727

Search for Magnesiocummingtonite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Magnesiocummingtonite Crystallography

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

Physical Properties of Magnesiocummingtonite

Cleavage:

{110} Good

Color:

Brown, Gray green, White, Light gray, Dark green.

Density:

3.13

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Silky

Streak:

white

Optical Properties of Magnesiocummingtonite

Optical Data:

NCalc= 1.64 - from Gladstone-Dale relationship (KC = 0.2058) where Ncalc=Dmeas*KC+1

Calculated Properties of Magnesiocummingtonite

Electron Density:

Bulk Density (Electron Density)=3.10 gm/cc
note: Specific Gravity of Magnesiocummingtonite =3.13 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_{Magnesiocummingtonite}= 4.81 barns/electron
U=PE_{Magnesiocummingtonite} x rElectron Density= 14.92 barns/cc.

Radioactivity:

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

Magnesiocummingtonite Classification

Dana Class:

66.01.01.01 (66)Inosilicate Double-Width Unbranched Chains, W=2

(66.01)with P=2 amphibole configuration

(66.01.01)Group 1, the Mg-Fe-Mn-Li amphiboles (Monoclinic)

66.01.01.01 Magnesiocummingtonite (Mg,Fe)7Si8O22(OH)2 C 2/m 2/m

66.01.01.02 Cummingtonite []Mg7Si8O22(OH)2 C 2/m 2/m

66.01.01.03 Grunerite []Fe7Si8O22(OH)2 C 2/m 2/m

66.01.01.03b Permanganogrunerite! []Mn4(Fe)3(Si8O22)(OH)2 C 2/m 2/m

66.01.01.04 Manganocummingtonite Na(Na,Mn)2(Mg4,Fe)5Si8O22(OH)2 C 2/m 2/m

66.01.01.05 Manganogrunerite []Mn2Fe5Si8O22(OH) C 2/m 2/m

66.01.01.06 Magnesioclinoholmquistite? Li2(Mg,Fe)3Al2Si8O22(OH)2 C 2/m 2/m

66.01.01.07 Clinoholmquistite? [](Li2Mg3Al2)Si8O22(OH)2 C 2/m 2/m

66.01.01.08 Clinoferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 C 2/m 2/m

66.01.01.08a Ferri-clinoholmquistite! []Li2Mg3(Fe3)2(Si8O22)(OH)2 C 2/m 2/m

66.01.01.08b Ferri-clinoferroholmquistite! []Li2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m

66.01.01.09 Sodic-ferripedrizite! Na(LiNa)(Fe2Mg2Li)Si8O22(OH,F)2 C 2/m 2/m

66.01.01.09a Ferripedrizite! NaLi2(Fe2Mg2Li)Si8O22(OH)2 C 2/m 2/m

66.01.01.09b Sodic-ferri-ferropedrizite! NaLi2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m

66.01.01.09c Fluoro-sodic-pedrizite! NaLi2(Mg2Al2Li)S5Si8O22F2 C 2/m 2/m

Strunz Class:

09.DE.05 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DE -Inosilicates with 2-periodic double chains, Si4O11; amphibole family

09.DE.05 Ferro-anthophyllite []Fe7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Anthophyllite []Mg7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Ferrogedrite []Fe5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Gedrite []Mg5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Ferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Holmquistite [](Li2Mg3Al2)Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Cummingtonite []Mg7Si8O22(OH)2 C 2/m 2/m

09.DE.05 Clinoferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 C 2/m 2/m

09.DE.05 Grunerite []Fe7Si8O22(OH)2 C 2/m 2/m

09.DE.05 Magnesiocummingtonite (Mg,Fe)7Si8O22(OH)2 C 2/m 2/m

09.DE.05 Manganogrunerite []Mn2Fe5Si8O22(OH) C 2/m 2/m

09.DE.05 Magnesioanthophyllite? (Mg,Fe)7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Protomangano-ferro-anthophyllite! (Mn,Fe)2(Fe,Mg)5(Si4O11)2(OH)2 Pnmn 2/m 2/m 2/m

09.DE.05 Sodicgedrite NaMg6AlSi6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Sodic-ferro-anthophyllite! NaFe7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Sodic-ferrogedrite! NaFe6AlSi6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Sodicanthophyllite NaMg7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Permanganogrunerite! []Mn4(Fe)3(Si8O22)(OH)2 C 2/m 2/m

09.DE.05 Protoferro-anthophyllite! (Fe,Mn)2(Fe,Mg)5(Si4O11)2(OH)2 Pnmn 2/m 2/m 2/m

09.DE.05 Fluoro-sodic-pedrizite! NaLi2(Mg2Al2Li)S5Si8O22F2 C 2/m 2/m

09.DE.05 Sodic-ferri-ferropedrizite! NaLi2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m

09.DE.05 Manganocummingtonite Na(Na,Mn)2(Mg4,Fe)5Si8O22(OH)2 C 2/m 2/m

09.DE.05 Protoanthophyllite! (Mg,Fe)7Si8O22(OH)2 Pnmn 2/m 2/m 2/m

09.DE.05 Ferri-clinoferroholmquistite! []Li2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m

09.DE.05 Sodic-ferripedrizite! Na(LiNa)(Fe2Mg2Li)Si8O22(OH,F)2 C 2/m 2/m

09.DE.05 Ferripedrizite! NaLi2(Fe2Mg2Li)Si8O22(OH)2 C 2/m 2/m

Other Magnesiocummingtonite Information

See Also:

Links to other databases for Magnesiocummingtonite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - Ecole des Mines de Paris
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - MinMax(Deutsch)
10 - MinMax(English)
11 - Mineralienatlas (Deutsch)
12 - QUT Mineral Atlas
13 - Ruff.Info

Search for Magnesiocummingtonite using:

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

Visit our Advertisers for Magnesiocummingtonite :

AA Mineral Specimens

B & L Fine Minerals

Crystalarium.com

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Desert Winds Gems and Minerals

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

Wrights Rock Shop

Translate Magnesiocummingtonite Mineral Data :

Ask about Magnesiocummingtonite 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 Magnesiocummingtonite Specimen Label here :

Magnesiocummingtonite

(Mg,Fe++)7Si8O22(OH)2
Dana No: 66.01.01.01 Strunz No: 09.DE.05
Locality:

Notes: