For many people over 50, seeing these hard, brown, deeply ridged seeds can instantly bring back memories of a grandmother’s kitchen. They might have been stored in a small jar, carried home from a market, or kept among other traditional ingredients that younger generations rarely recognize today. Their unusual appearance makes them easy to mistake for nuts, dried fruit, or even something that isn’t meant to be eaten at all.

These are commonly known as Brazil nuts in their shells. Before the smooth, pale kernels reach grocery-store shelves, Brazil nuts are protected by an extremely hard, dark-brown shell with a rough, woody surface. Older generations were more accustomed to buying mixed nuts still in their shells and cracking them at home, especially around holidays.

Getting to the edible portion required some effort. The shell is exceptionally tough, so families often used a sturdy nutcracker rather than trying to open it with their hands. Once cracked, the familiar creamy Brazil nut could be removed and eaten on its own or added to desserts, cakes, cookies and homemade nut mixtures.

Brazil nuts are also notable nutritionally because they’re exceptionally rich in selenium, an essential mineral involved in normal thyroid and immune function. But that concentration is also why eating huge quantities isn’t a good idea. A small amount can provide plenty of selenium, while regularly consuming excessive amounts can push intake beyond recommended levels.

So if these immediately reminded you of something sitting in your grandmother’s pantry, your memory wasn’t playing tricks on you. They’re Brazil nuts still inside their natural hard shells, a sight that was once much more familiar when families routinely bought nuts before they had been shelled and packaged for convenience.