A great source for organic walnut shell halves used in ornaments and natural art supplies.
If you need walnut shell "grit" for polishing metal or water filtration, specialized industrial suppliers offer bags ranging from 10 lbs to 1-ton "jumbo" bags. Walnut Shell Blasting Media Grit - Kramer Industries
Walnut shells are a versatile resource available through various channels depending on whether you need them for crafting, industrial sandblasting, or gardening.
For smaller quantities (11 oz to 10 lbs), major e-commerce platforms offer crushed, ground, or whole shells.
Often lists unique natural handmade ornaments and bulk lots of shell pieces.