Unexfoliated vermiculate has a few minor uses, such as for circulation in drilling mud and in the annealing of steel. When unexfoliated vermiculate is reacted with concentrated H2SO4, it produces a pure form of silica in flake form. This product is known as 'samisilite'. It is used as adehydrating medium in air conditioning plants since it can absorb about 20 per cent its weight of water. The potency of this product may be revived by heating.