Bridging oxygen

Bridging oxygen

Non-bridging oxygen

Apical oxygen

Ca2Si2O6

Mg2Si2O6

Fe2Si2O6

Ca

Mg Fe

Ca

Mg Fe

Quad Pyroxenes

Ca

Mg Fe

Quad Pyroxenes

Pyroxenoids

Ca

Mg FeEnstatite Ferrosilite

Wollastonite

Ca

Mg Fe

Diopside Hedenburgite

Ferrosilite

Ca

Mg Fe

Diopside Hedenburgite

Pigeonite

Ferrosilite

Ca

Mg Fe

Diopside Hedenburgite

Pigeonite

Augite

Enstatite Ferrosilite

Ca

Mg Fe

Diopside Hedenburgite

Pigeonite

Augite

Enstatite Ferrosilite

Amphibole Site Nomenclature

W0-1 X2 Y5 Z8O22 (OH,F)2

W = ions in A site, 10-12 coordinated (Na, K)

X = ions in 2 M4 sites, 6-8 coordinated (Mg, Fe2+, Ca, Na)

Y = ions in 5 octahedral M2, M1, M3 sites (Mg, Fe2+, Fe3+, Al, Ti)

Z = Si or Al in tetrahedral sites

Chemistry of Amphiboles Name W0- 1 X2 Y5 Z8 tremolite Ca2 Mg5 Si8 O22(OH)2 anthophyllite Mg2

Mg5 Si8 O22(OH)2

gedrite Mg2 (AIMg4) (AISi7) O22(OH)2

___________________________________________________________________ tremolite Ca2 Mg5 Si8 O22(OH)2

tschermakite Ca2 (AIMg4) (AISi7) O22(OH)2

pargasite Na Ca2 (AIMg4) (AI2Si6) O22(OH)2

____________________________________________________________________ tremolite Ca2 Mg5 Si8 O22(OH)2

edenite Na Ca2 Mg5 (AlSi7) O22(OH)2

pargasite Na Ca2 (AlMg4) (AI2Si6) O22(OH)2 ___________________________________________________________________ tremolite Ca2 Mg5 Si8 O22(OH)2 ferroactinolite Ca2 Fe5 Si8 O22(OH)2 grunerite Fe2 Fe5 Si8 O22(OH)2

___________________________________________________________________ tremolite Ca2 Mg5 Si8 O22(OH)2 gluacophane Na2 (AI2Mg3) Si8 O22(OH)2

ferroglaucophane Na2 (Fe2+3Mg3) Si8 O22(OH)2

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