Maybe you mean the kind of orangey-pink, blocky crystals in granite-like rocks? One in a while they happen to weather out and are found by themselves. Those are a kind of feldspar, calcium-rich if I remember rightly. Some are a more pale candy-pink than orangey - it varies with the chemistry. Big feldspar crystals mostly form in igneous rocks, actually the kind of igneous rocks that crystallize while cooling slowly deep in the Earth's crust. Volcanic rock - lava that cools into flows, with few or no crystals - is also igneous, and may have the same chemicals, but has cooled too slowly to form big crystals.
My guess for the blue stuff in Wrightwood (and Blue Cut, which is along another part of the San Andreas) is that it is a slightly more metamorphosed kind of rock than actinolite. There is a rough scale of metamorphosis that uses color, a "green facies" as opposed to a "blue facies", with the blue stuff being more metamorphosed - more highly cooked, more pressured and more torn-up and twisted - than the green kind, which is where the actinolite is usually classed. The color is only a rough guide, but since the San Andreas runs through this part of the state, it's a slam-dunk that there is plenty of very torn up, very highly metamorphosed rock here - as opposed to places where the fault action hasn't been that strong over the centuries. And - the more metamorphosed it is, the faster it degrades and weathers into that gooey blue clay. The fine clay particles are what travel so far out in the alluvial fan, from the stream mouth out into the desert floor. That's why we always know where Wrightwood is on TV airphotos - that distinctive bluish fan!
The old-fashioned way to prospect for mineable riches was to wander around with your burro and pay attention to the rocks around you. I wouldn't be surprised if the Blue Cut name was from those times. Fault zones are often great places to find riches.
