Broken beads of self-indicating (not-hazardous) silica gel, light micrograph. It is an amorphous solid, a mesoporous (pore opening sizes: 2-50 nm), granular, vitreous form of silicon dioxide (silica), synthetically obtained from sodium silicate. It is a tasteless, odorless, non-toxic, non-corrosive, and chemically inert desiccant. Its interconnected pores have a high specific surface area (around 800 m?g) which attracts and holds water by adsorption and capillary condensation, allowing it to adsorb up to 40% of its weight. Water molecules adhere to the silica gel bead surface because it exhibits a lower vapor pressure than the surrounding air. Uses: chromatography, catalysis, food additive (E551), preservation (museum pieces, goods, drugs), water filtration, humidity indicator, cat litter, etc. Field of view size: 5.88 x 8.83 mm (0.232 x 0.348 in)