Silica is a very hard and durable mineral. It is found in nature as sand or quartz and is the primary raw material for most types of glass, as well as being a component of many ceramic glazes and the main ingredient in Portland cement. It is also the source of silicon dioxide (SiO2), which is used to produce optical fibers for telecommunication.
When exposed to air, silica will slowly oxidize and lose some of its strength. However, this process is slowed by the presence of moisture in the air. That is why it is important to store items containing silica in an environment with low humidity and no direct sunlight.
In its crystalline form, silica is highly toxic to humans. However, in its amorphous form, it has been shown to pose minimal risk to human health. The FDA has set standards that must be met to ensure a safe level of exposure.
The high melting and boiling point of silica is due to the fact that it has strong covalent bonds between its atoms. This is in contrast to ionic bonds that tend to weaken as the temperature of a substance rises.
Adding a pack of silica gel to your seasonal storage can help keep your items dry and prevent mildew. It is also an excellent addition to any container storing medication or spices as these products can easily absorb moisture and become stale. You can find silica gel packs in most grocery stores and pharmacies.