Skeleton formulas

Question 1

Framework Silicates

Answer 1

^VII-XII A _0-2 [T₄O₈]

Question 2

T-O-T and T-O-T-A sheet silicates

Answer 2

^XIIA_0-1 ^VIM_2-3 {T₄O₁₀](OH)₂
Ex: talc _ Mg3Si4O10(OH)2

Question 3

T-O and T-O-T-O sheet silicates

Answer 3

^VIM_4-6 {T₄O₁₀](OH)₈
Ex: chlorite or serpentine

Question 4

Amphiboles

Answer 4

^XIIA_0-1 ^VIIIM₂^VIM₅ {T₈O₂₂](OH)₂
Ex: Tremolite - _ Ca2Mg5T8O22(OH)2

Question 5

Pyroxenes

Answer 5

^VI-VIIIM ^VIM {T₂O₆]

Question 6

Zircon type nesosilicates

Answer 6

^VIIIM {TO₄]

Question 7

Olivine nesosilicates

Answer 7

^VIM ^VIM {TO₄]

Question 8

Nesosilicates with extra O, OH, and F

Answer 8

^IV-VIIIM ^VIM {TO₄]O
Ex: kyanite Al2O[SiO4]

Question 9

Garnets and similar nesosilicates

Answer 9

^VIIIM ₃ ^VIM ₂ {TO₄]₄

Question 10

Isometric system

Answer 10

a=b=c
α=β=γ=90

Question 11

Trigonal

Answer 11

a=b=c
α=β=γ=\90

Question 12

tetragonal

Answer 12

a=b=\c
α=β=γ=90

Question 13

hexagonal

Answer 13

a=b=\c
α=β=90 γ=120

Question 14

Orthorhombic

Answer 14

a=\b=\c
α=β=γ=90

Question 15

Monoclinic

Answer 15

a=\b=\c
α=γ=90 β=\90

Question 16

triclinic

Answer 16

a=\b=\c
α=\β=\γ=\90