Agate beach, Bolinas
What you can find: "Oil" agates, fossil shells, petrified bone.
Ease of access: Very easy.
Equipment needed: A good pair of eyes and a specimen bag.
Safety considerations: Keep an eye on the ocean.
Where, exactly? At the end of Elm Road in Bolinas.
Agate Beach in Bolinas, California is listed in many rockhound guides for the abundant, small agates with black inclusions found here, known as Oil Agates. Some claim these black specks are actually oil suspended within the agate
Best collecting is during the winter, after large storms have washed new material onto the beach.
The Oil Agates were small, none bigger than my thumbnail, but I collected a good handful - they seemed quite abundant.
However, these were not the only offerings Agate Beach had. Although it was poor weather and turning towards dusk when I visited, I quite quickly began to find small pebbles of petrified whalebone.
I didn't see any large pieces, but the pebbles seemed to come in all kinds of colors, from red to black to orange to white, all with the distinctive bone texture.
I assume there must be large pieces to be found in the area as well, for one who had the time to look more extensively - the material is probably weathering out of the nearby cliffs.
I came up with quite a decent handful of bone pebbles in only a short while of collecting, and also spotted a few little fossil seashells amid the gravel, somewhat surf-worn but still fresh enough to make out some of the details in the shells.
And if nothing else, you can have a lovely walk on the beach - the scenery is lovely at any time of the year in Bolinas.