There is mainly two types of silica gel available in market.
Indicating type Silica Gel
In this indicating type silica gel there is also two types of silica gel available
in market based on their color changing phenomena.
Blue Indicating Type Silica gel
It appears dark blue in color when free from moisture and gives indication from
dark blue to pink when it absorb moisture.cobalt chloride is use for blue to pink
indication.
Orange Indicating Type Silica gel
In this type there is also two sub type of Orange Indicating silica gel.
Non Indicating type Silica Gel
t appears in white transparent silica gel. It will not give any clear visual indication
of color when it completely hydrated.