SILICATE TETRAHEDRONS

Question 1

advanced grouping of silicates

Answer 1

tetrahedrons

isolated tetrahedron silicate minerals

chain silicate minerals(double/single)

sheet silicate minerals

framework silicate minerals

Question 2

isolated tetrahedron silicate mineral properties

Answer 2

only bonded to Si and O4, with strong covalent bond but weak ionic bond with fe/mg

physical property of being equally strong in all directions

iron-rich, e.g olivine/garnet

Question 3

chain silicate minerals(single/double) properties

Answer 3

silicate tetrahedron form long chains with silicon atoms sharing oxygen atoms with neighbouring tetrahedron

strong covalent bond but weak ionic bond with fe/mg

single, sharing 1/4 oxygen atoms, double, sharing 2/4 oxygen atoms

tend to be iron-rich, e.g pyroxene/hornblende

Question 4

sheet silicate minerals properties

Answer 4

form 2-dimensional sheets with silicon atoms sharing 3/4 oxygen atoms with surrounding tetrahedrons

strong covalent bond but weak ionic bond with fe/mg

tend to break in flat layers along weak bonds between sheet, resulting in soft minerals

iron-rich or iron-free silicates present, e.g biotite mica

Question 5

framework silicate minerals properties

Answer 5

form 3-dimensional framework with silicon atoms sharing all their oxygen atoms

strong covalent bond amount all atom, mineral is hard

iron free silicates, quarts

Question 6

charge of SiO4

Answer 6

-4