These are whole dried turmeric rhizomes, the form turmeric is traded in before it reaches a mill. Hard, dense and deeply coloured all the way through when snapped.
Grinding your own is more effort, and there are two real reasons to do it. The first is that whole fingers hold their oil and colour for years where ground turmeric fades within months. The second is verification. Turmeric is one of the most adulterated spices in the world, and a whole rhizome cannot be bulked out with starch or brightened with dye. You can see what it is.
A spice grinder handles them, though they are genuinely hard, so work in small batches and expect to hear about it. A heavy mortar works too if you have patience.
Also used whole. Simmered in broth, dropped into pickling liquid, or grated fresh like ginger.
