From what I see it's pretty much country rock consisting primarily of quartz with no prize. I use to live in Fair Oaks, not far from you there in Citrus Heights
I agree with Tamrock, definitely quartzite material of some sorts, just not the gold containing type.
Lots of gold was dredged out of that area back in the day, but this far down in the valley they were mining gold dust and small flakes, no nuggets bigger than a plinker were to be found in the buried stream beds of the American River.
To find nuggets or vein gold, you gotta go East and up in elevation.
I'm in Folsom, there's gold dust to be found in most of the creeks of the area, but unless you're dredging or sluicing, hardly worth the effort.
I've panned nice large "Sassy Flakes" from both the north fork and the south fork of the American just a few miles east of Folsom Lake.