Different Types of Crystals

Isometric

• Isometric crystals are formed with the same lengths along all axes. They can have four faces (cubes), eight or ten, all of equal sizes.

Hexagonal

• These crystals have six flat faces of the same size. When cut in half, the cross-section of these crystals will form a hexagon.

Covalent Crystals

• These crystals have covalent bonds between all the molecules that make them up, meaning that electrons are shared between bonded molecules. These can be looked at as one giant molecule, and they typically have very high melting points.

Ionic Crystals

• The molecules in these types of crystals are held together by electrostatic forces. They are very hard; one example of this type of crystal is common table salt.

Molecular Crystals

• These types of crystals are very soft, as opposed to other types of crystals. This is because their bonds are noncovalent and weak, such those formed with hydrogen.