Spice grinders

There are two main spice grinders used in Sri Lanka: a heavy stone base with a stone rolling pin; and a massive wooden mortar and pestle. I find an average-sized sturdy mortar and pestle is usually sufficient, and I like to use a spice grinder for spices that are too hard to grind in the mortar. I also like to use the spice grinder for ingredients such as Maldive fish, sprats and green gram.