Tweedle-dum and Tweedle-Dee: Phase Transitions

Myrmektite

Solid State Phase Transformations

Solid State Phase Transformations

Solid State Phase Transformations

Solid State Phase Transformations

Solid State Phase Transformations

Solid State Phase Transformations

Silica: Rapid Cooling

Silica: Rapid Cooling

Silica: Rapid Cooling

Metastable tridymite and cristobalite are common in acid volcanic rocks

Silica: Rapid Cooling

Silica: Rapid Cooling

Silica: Rapid Cooling

Solid State Phase Transformations

Solid State: Exsolution

Alkali Feldspar

High Temperature Alkali Feldspar

Found in volcanic rocksAnorthoclase, Mt Erebus

Low Temperature Alkali Feldspar

Found in plutonic rocks

Low Temperature Alkali Feldspar

Found in plutonic rocks

Plagioclase Feldspar

Plagioclase Feldspars

Two Feldspars

Perthite

Microcline without perthite and anorthite

Pyroxenes

Pyroxenes

Ca-poor Px Ca-rich Px

Augite

Tem

pera

ture

Pyroxenes

Inverted Pigeonite

001

100

Thickest along the 001 plane

Iron Meteorites and Cooling Rates

Widmanstatten Texture

Kamacite (low-Ni metal)Taenite (high-Ni metal)

Iron Meteorites and Cooling Rates

Liquid Immiscibility

Liquid Immiscibility

Liquid Immiscibility

Oldoinyo LengaiGregory Rift, Tanzania

Liquid Immiscibility

Natrocarbonatite lavas

Natrocarbonatite Lava

Liquid Immiscibility

Explosive eruptions of mixed silicate (nephelinite) – carbonatite ash

Carbonatite melt exsolves by liquid immiscibility from a nephelinite magma chamber