Mineralogy and Petrology Flashcards
Name 3 alluminosilicates
kyanite, andalusite and sillimanite
Forsterite and Fayalite are in what mineral group?
Olivines
The 2 main isolated orthosilicates?
Olivine and garnet
The 2 single chain inosilicates?
Orthopyroxene and Clinopyroxene
What ranges the orthopyroxenes
Ensatite to ferrisolite
Extinction angle of OPX’s
0
Extinction angle of CPX’s
30 to 60
Enstatite, Ferrosilite are what?
Orthopyroxenes
Chemical formula for Enstatite?
Mg2Si2O6 or Mg2SiO3
Chemical formula for Ferrosilite?
Fe2Si2O6 or Fe2SiO3
Diopside and Hedenbergite are what?
Clinopyroxenes
Chemical formula for Diopside?
CaMgSi2O6
Chemical formula for Hedenbergite?
CaFe2+Si2O6
Describe an Eclogite
Metamorphic rock containing garnets and pyroxenes
How are double chain tetrahedra formed?
If two single chain tetrahedra can share three of their oxygens
What mineral group is Amphibole?
Double chain - Inosilicate
Name 4 amphiboles
Hornblende, anthophyllite, tremolite and pargasite
What is the general formula for amphiboles??
AB2C5T8O22W2 or replace W with OH2
What mineral group has variable coordination numbers??
Amphibole
Anthophillites mineral formula??
Mg2Mg5Si8O22(OH)2
Mineral group for cummingtonite?
Amphibole
For a sheet silicate, what is the tetrahedral part?
(Si2O5)2-
For a sheet silicate, what is the octahedral part?
Mg(OH)2, Mg3(OH)6 or Mg3(OH)3(OH)3
Name the hydroxide mineral made of sheets of octrahedra
Brucite