Juglans nigra, the eastern black walnut
the eastern black walnut has the hardest shell of any nut in the world,
but a unique fruity taste, and delicious health benefits.
HARVESTING:
Black walnut hulls contain juglone (5-hydroxy-1,4-naphthoquinone), plumbagin (yellow quinone pigments), and tannin. These compounds cause walnuts to stain cars, sidewalks, porches, and patios, in addition to the hands of anyone attempting to shell them (for weeks), and are usable as a dark ink or wood stain, and possibly temporary tattoos like henna.
Dehull nuts, and save hulls in water to make natural and safe, anti-fungal-tincture, herbicide, yellow-brown ink, or dye.
Place shelled nuts in water... remove any that float.. let others soak to remove hull particles...
Or wait for the pods to dry and turn black, then hammer away the black pod, then water soak.
Dry and store the nuts for a month or two, meats will cure, and shrink, and be easier to crack.