Oakland has not only rocks, but also stone to admire. The grand McElroy Fountain of Lakeside Park, newly refurbished and 100 years old this year, displays monumental marble to advantage.
Here’s a page from Annalee Allen’s book Oakland about the fountain and its namesake, a Flickr page with some discussion of the project, and a set of closeups of the (wildly misinterpreted) bronze panels by Douglas Tilden around the fountain depicting stages of life.
I didn’t find any information about the stone, but this grade of marble was easily available from domestic and foreign sources in 1911. Oakland was a big stoneworking town with many skilled European craftsmen, a major regional cemetery, a booming construction industry and good freight service by rail and sea.