Presenter Information

Jacob Wall, Colby CollegeFollow

Location

Parker-Reed, SSWAC

Start Date

1-5-2014 1:00 PM

End Date

1-5-2014 2:00 PM

Project Type

Poster

Description

Augite is typically known for its greenish black color, nice vitreous luster, two directions of cleavage and of course its simple chemical formula: (Ca,Na,Mg,Fe2+,Fe3+Al,Ti)2[(Si,Al)2]O6]. Augite has a hardness of 5.5, 2 planes of cleavage and massive habit. Augite is an important rock-forming silicate mineral and occurs in a wide variety of basic igneous rocks, including gabbros, dolerites and basalts. Augite also occurs in ultrabasic and intermediate rocks as well as a limited number of high-grade metamorphic rocks such as granulites and charnockites. Augites range widely in composition and show a continuoius variation in chemical composition. Iron rich augites are restricted to occurring in ferrogabbros, iron-rich dolerites, syenites, acid volcanic glasses and metamorphosed iron formations. Augites optical properties are as follows. Augite has first and second order interference colors, weak pleocrhoism and an extinction angle at 45. Simple twinning and two planes of cleavage at 90 to each other are present in Aguite in thin section. Augite is a biaxial monoclinic mineral with positive optic sign.

Faculty Sponsor

Tasha Dunn

Sponsoring Department

Colby College. Geology Dept.

CLAS Field of Study

Natural Sciences

Event Website

http://www.colby.edu/clas

ID

351

Included in

Geology Commons

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May 1st, 1:00 PM May 1st, 2:00 PM

My Pet Mineral: Augite

Parker-Reed, SSWAC

Augite is typically known for its greenish black color, nice vitreous luster, two directions of cleavage and of course its simple chemical formula: (Ca,Na,Mg,Fe2+,Fe3+Al,Ti)2[(Si,Al)2]O6]. Augite has a hardness of 5.5, 2 planes of cleavage and massive habit. Augite is an important rock-forming silicate mineral and occurs in a wide variety of basic igneous rocks, including gabbros, dolerites and basalts. Augite also occurs in ultrabasic and intermediate rocks as well as a limited number of high-grade metamorphic rocks such as granulites and charnockites. Augites range widely in composition and show a continuoius variation in chemical composition. Iron rich augites are restricted to occurring in ferrogabbros, iron-rich dolerites, syenites, acid volcanic glasses and metamorphosed iron formations. Augites optical properties are as follows. Augite has first and second order interference colors, weak pleocrhoism and an extinction angle at 45. Simple twinning and two planes of cleavage at 90 to each other are present in Aguite in thin section. Augite is a biaxial monoclinic mineral with positive optic sign.

http://digitalcommons.colby.edu/clas/2014/program/187