What is silica and where is it found?

Silica is a common naturally occurring mineral, also known as silicon dioxide. One common type of crystalline silica is quartz. Silica can be found or manufactured in different forms, broadly divided into crystalline and non-crystalline (amorphous). This information focuses on respirable crystalline silica, which is the more hazardous form. 

Silica is a major constituent of many types of sand. It is also a component of concrete and some bricks and rocks (eg granite, slate, sandstone). As such, this hazard can be found in industries such as construction, masonry, mining and foundries.