Technically, silica gel is a xerogel of silicic acid that has a strong absorbing property. It is not a gel at all, but a granular substance that closely resembles sugar. Flowers are completely submerged in this substance in order to be preserved. Silica granules are very light weight and allow flowers to keep their shape. Each grain of silica can absorb up to 40% of its own weight in moisture. This process takes approximately 7 days to dry the flowers completely.