When a mineral can be transform its chemical composition but maintain crystalline structure due to similar pressure and temperature conditions

When two minerals have the same chemical composition but different crystal structures due to differing pressure and temperature conditions

When a mineral is the protolith for many different rocks

When an intrusion metamorphosizes surrounding rocks

Granite and Rhyolite are low in silica composition, Basalt and Gabbro are high in silica composition. Granite and Basalt crystallize underground, and Rhyolite and Gabbro crystallize at the surface.

Granite and Rhyolite are high in silica composition, Basalt and Gabbro are low in silica composition. Granite and Basalt crystallize at the surface, and Rhyolite and Gabbro crystallize underground.

Granite and Rhyolite are high in silica composition, Basalt and Gabbro are low in silica composition. Granite and Gabbro crystallize underground, and Rhyolite and Basalt crystallize at the surface.

Granite and Rhyolite are low in silica composition, Basalt and Gabbro are high in silica composition. Granite and Rhyolite crystallize at the surface, and Basalt and Gabbro crystallize underground.

Granitic magma has low silica content and thus cools faster underground, Basaltic magma has high silica content and is more likely to erupt at the surface.

Basaltic magma has low silica content and thus cools faster underground, Granitic magma has high silica content and is more likely to erupt at the surface.

That minerals melt and crystallize at the same temperature.

That minerals have the same crystallization temperatures, but as the magma cools the composition changes due to it being either basaltic or granitic magma.

That different minerals have different crystallization temperatures, and thus crystallize in a sequence as magma cools and its composition changes.

Intrusive rocks

Extrusive rocks

the higher the viscosity

the lower the viscosity