It’s been a while, but lately I’ve returned to walking in the Broadway Terrace/upper Rockridge neighborhood, where this Franciscan knocker sits. This is a disrupted deep-sea chert that has been heavily altered, bleaching out its color.
(See the first set from upper Rockridge here.)
It’s across Ocean View Drive from the chert cluster I showed almost three years ago, at the top of the stairway called Brookside Lane. (I like that this path and West Lane have “grownup” names instead of “X Steps” or “Y Path” like all the other footpaths up here.)
I may be wrong in calling this a knocker; it is more likely to be a boulder that was moved here. But it’s certainly local. There’s a variety of highly altered rock in parts of the Franciscan called calc-silicate, and it might look like this; I haven’t gotten a handle on it yet. That would have started out as a dirty limestone, though, and this looked like a chert. I didn’t have a magnifier with me, and of course I can’t hammer it. Darn, I’ll just have to come back.