Silica Gel Blue is a synthetic, amorphous form of silicon dioxide containing an indicator, cobalt chloride, which changes color in response to moisture levels. The beads have a dark blue appearance when they are packed and dry. However, once the Silica Gel Blue absorbs moisture and becomes saturated, it turns pink, indicating that it needs to be replaced with fresh material or regenerated. This self-indicating desiccant is semi-transparent and available in both bead and crystal forms.