It's a flinty kind of smell. But "flinty" is a word used to describe white wines, while "wet gravel" is more likely found in descriptions of red wines, especially ones made with Cabernet Franc or ...

These are the bottles that best express Pinot Noir and Merlot grape varieties. Cabernet Sauvignon may be the world’s most popular red wine, but Pinot Noir and Merlot have long been fan favorites.