Blue Silica Gel Powder is a moisture-absorbing desiccant just like white silica gel, but with a twist: it contains a moisture indicator, making it super handy when you need to see when it's saturated. What Is Blue Silica Gel Powder? Base Material: Amorphous silicon dioxide (SiO₂), like white silica gel. Color Indicator: Contains Cobalt(II) chloride, which makes it blue when dry and pink or purple when saturated. Form: Fine granules or powder (less common in powder form than bead form, but still used).