Silica gels are synthetic amorphous products of pure SiO₂.
They are used e.g. as:

• Matting agents in paints
• Ink receptive media
• Cleaning agents in toothpastes
• Flavor carriers
• Free-flow agents
• Purification aids in oil and beer

Zeolites are crystalline alumino-silicates with narrowly defined pore structure, thus the term molecular sieves. Main usage is as:

• Moisture adsorbent e.g. in insulating glass windows and refrigeration systems
• Drying and purification of petrochemicals, natural and industrial gases and liquids.

Colloidal silicas are aqueous colloidal dispersions of very small silica particles. They are used as:

• High temperature binders in investment casting and refractory fibers
• Binders
• Ink reception in the receiver layer of high-gloss photo inkjet media

Precipitated silicas are also synthetic amorphous silica products, but with a different structure than silica gels. They are used as:

• Reinforcing agents for rubber and tires
• Carriers and free-flow agents
• TiO₂ extenders
• Fillers in papers