Agate Beach is the only sandy beach within Patrick's Point State Park, which otherwise has a rugged and rocky coastline. The beach stretches far to the north where it becomes Big Lagoon County Beach. To the south the beach quickly turns into the more characteristic rocky cliffs found around Patrick's Point State Park. The rest of Agate Beach is backed by tall silty cliffs with exception of the small canyon where the access trail leads. This sandy and pebbly beach is most popular for the hunting of agates.
Despite some common myths, agates are not pieces of glass that have been smoothed out which can be found on Glass Beach along the Mendocino Coast. Instead, an agate is a rock formed from cryptocrystalline silica (minute silica crystals). The crystals of agates found on Agate Beach are so small that they cannot usually be seen with the naked eye and instead form a clear glass-like rock with bands of color. The most common colors of agates found on agate beach are white/clear, rose, and orange. Beachcombers typically search for agates early morning after a high tide event when the waves have cleared. Careful inspection can often yield small agates while sifting through the pebble bunches that have been above the high tide level for quite some time.