Siliceous soils are formed from rocks that have silica (SiO2) as a principal constituent. The parent material of siliceous soils may include quartz sands, chert, quartzite, quartz reefs, granite, rhyolite, ademellite, dellenite, quartz sandstone, quartz siltstone, siliceous tuff, among others.[1] These parent materials sometimes originate from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges.[2]