There are many different types of cat litters available, but essentially most of them fall into three distinct categories: clay-based, silica-based, and biodegradable. The best cat litter for your cat will depend on your expectations. Clay cat litters are the oldest type of commercial cat litter and are still widely available.
Clay is used in cat litters because of its ability to absorb liquid. Traditional clay litter can absorb its weight in cat urine and, because it separates the urine effectively, has some natural odor control as well. Crystallized cat litters are formed from a silica gel. This gel is absorbent and also provides odor control.
The silica used in these products is similar to the desiccant that is often found in the pouches packaged as a preservative with foods, medications, and other consumables that can be damaged by excess moisture. Silica-based cat litters provide an option for those who prefer a non-clay litter.
Though a large quantity of either clay or silica litter would need to be ingested to really be dangerous to your cat, biodegradable cat litters provide an alternative for those who are concerned about that possibility. They also provide an alternative for those who prefer a more ecologically friendly “green” product.