Tectosilicates
Capped quartz showing crystal faces: SiO{{< sub 2 >}}.
Quartz crystals: SiO{{< sub 2 >}}.
Quartz (agate): SiO{{< sub 2 >}}.
Albite crystals: NaAlSi{{< sub 3 >}}O{{< sub 8 >}}.
Albite crystals showing cleavage faces: CaAl{{< sub 2 >}}Si{{< sub 2 >}}O{{< sub 8 >}}.
Intergrown K-Feldspar crystals and fragment showing perthite lamelli: KAlSi{{< sub 3 >}}O{{< sub 8 >}}.
K-Feldspar showing perthite lemelli: KAlSi{{< sub 3 >}}O{{< sub 9 >}}.
K-Feldspar: KAlSi{{< sub 3 >}}O{{< sub 10 >}}.
Leucite crystals in basalt: KAlSi{{< sub 2 >}}O{{< sub 6 >}}.
Intergrown sodalite: Na{{< sub 8 >}}(AlSiO{{< sub 4 >}}){{< sub 6 >}}Cl{{< sub 2 >}} and nepheline: (Na,K)AlSiO{{< sub 4 >}}.
