Excise - ssi exemption - urgent

X, an SSI, is a marble processing unit. X does sandstone sawing i.e. converting sandtone blocks into slabs on a gangsaw.

Now converting Sandstone blocks into slabs amounts to manufacture and sandstone is also appearing in the tariff.

But in the tariff the rate of excise duty on sandstone is nil.

Now I am confused whether this sandstone sawing will be added while calculating the limit of Rs 400/150 lakhs.

Please guide.

Thanks.

Sheetal