Abrasives are made from substances that can be reduced to very small, very hard particles. Abrasives are used for things like drilling, grinding, polishing, and scouring. How small, and how hard the particles are varies. Generally, the very hardest are made from the hard minerals (like diamond), while the softer abrasives come from organic sources like shells and kernels.
Toothpaste is a mild abrasive paste used to scour and polish your teeth. In most toothpastes, the abrasive grit is calcium carbonate (also a common ingredient of seashells and limestone). FYI, toothpaste also makes a great silver polish. I’ve used it on my antique silver jewelry and it’s awesome.
Made from seeds crushed after oil (wax) extraction. Used in things like facial cleanser. Photo from Purcell Jojoba, a family-owned jojoba farm and processor, right here in the U.S.