Rock cycle index

The Rock cycle

Rock formation

Erosion and weathering

Identification of rocks

Grain

Cementation

Crystal structures of rocks

Sedimentary

Metamorphic

Gems

Ores

 

 

 

Metamorphic Rocks - crystal structures

Serpentine

Mg₃ Si₂O₅ (OH)₄

Note the tetrahedral arrangement of the silicon at the center of 4 oxygens.

 

Garnet

Ca₃Fe₂Si₃O₁₂

Iron atoms (Fe) are at the center of octahedra. Again the structure is croos-linked by SiO₄ tetrahedra.

 

 

Andalusite

Al₂SiO₅

 

Note how the AlO₆ octahedra are cross-linked by SiO₄ tetrahedra.

© Ricardo Esplugas. All images in this site can be bought in an enlarged version. Please contact me on [email protected]