I think you found a piece of Franciscan Chert.
As a new rock hounder along the
Central California Coast, you'll want to learn what the Indians knew for some 14,000 years.
The chert made good, sturdy tools.
Go north, and you'll find the
Franciscan Cherts. To your south, the
Monterey Chert.
Your piece is older and riddled with quartz veins, which would be problematical for making tools.
Smoother, shinier pieces would be their preference.
It can be improved by heat treating (450 degrees for 24 hours, more if needed) They would place pieces in the sand beneath their fires.
Unfortunately, the quartz veins would still be a problem.
If you get a chance to walk the rivers towards your north, you'll find the green Franciscan Cherts become more and more common.
As you work your way up towards Eureka, you'd find it is available in a myriad of colors. Brown and green being the most common, and
very often selected by the Indians. It can be white, blue, red, orange, pink, gray, black, etc. ... also.
As you head south, you'll run into the Monterey Cherts. Mostly a black or dark rootbeer color. It was also used and traded by the Indians.
If you get a chance, stop by the Santa Barbara Natural History Museum. You'll see a lot of Monterey Chert artifacts used by the Chumash.
But, heading north, it's the Franciscan Cherts (which yours has all appearances of) that are prevalent.
Good luck in your rock hounding endeavors. California is large, and has a huge variety of possibilities.
