Lecture 10

Question 1

What are nesosilicates also known as?

Answer 1

Isolated tetrahedra

Question 2

What are single chain silicates also known as?

Answer 2

Inosilicates

Question 3

What are double chain silicates also known as?

Answer 3

Sorosilicates

Question 4

What are phyllosilicates also known as?

Answer 4

Sheet

Question 5

What are cyclosilicates also known as?

Answer 5

Ring

Question 6

What are framework silicates also known as?

Answer 6

Tectosilicates

Question 7

What are some characteristics of the nesosilicates?

Answer 7

Tetrahedra are linked by cations (mostly iron and magnesium). No shared oxygen electrons. Most frequent minerals on earth

Question 8

What is an example of a nesosilicate? (isolated tetrahedra)

Answer 8

Olivine (most frequent mineral on earth, dominates the mantle)

Question 9

What are the characteristics of inosilicates? (Single-chain)

Answer 9

Single covalent chains ionically bonded to each other by metals. Tough perpendicularly but weak in parallel direction.

Question 10

What are the characteristics of sorosilicates (double-chain)?

Answer 10

Covalent bonds between three oxygen molecules, cations ionically bonded (same toughness as single chain). Not rock forming minerals.

Question 11

What is characteristic of phyllosilicates (sheet)

Answer 11

Bonded like the double chain (covalent bonds between three oxygen molecules, cations bonded ionically) but form a plain of bonds. Same toughness as double chain and single chain. Huge variability in shape

Question 12

What type of silicate are the mica minerals?

Answer 12

Phyllosilicates (sheet)

Question 13

What are the 2 types of Mika?

Answer 13

Muscovite; White Mika’

Biotite: Black Mika

Question 14

What is characteristic of mica?

Answer 14

Toughest silicates perpendicularly, weakest parallel. Can detach to make flaky bits.

Question 15

Where does muscovite and biotite form?

Answer 15

Muscovite: Acidic domains, forms on continental plain

Biotite-forms in deeper parts of crust and mantle.

Question 16

What is characteristic of tectosilicates (framework)?

Answer 16

All 4 oxygen atoms are bonded with covalent bonds. 3 dimensional framework, most diverse. Cations represent impurities.

Question 17

What is an example of a tectosilicate?

Answer 17

Quartz-most frequent mineral in the crust. Extremely resistant, not prone to dissolution.

Question 18

What is characteristic of the cyclosilicates? (ring)

Answer 18

Rings share 2 oxygen atoms, form rings of 3 or 4 or 6 tetrahedra. Not rock forming. Relatively rare.