Long time ago, before the major up lift of the west coast plates...and the creation of the Sierra Nevada Mountains, and before the rivers started to run east and west in what is now California, the rivers ran mostly north to south... one of those rivers had a blue color to the sand, blue stained rocks and was usually very rich in gold.... Pieces of this river were found in the deserts of California, the northern mountains of California and Oregon... No one knows for sure the actual route the river ran, but it is usually and generally accepted it ran from somewhere in Canada to Mexico and near the present day Sierra Mountains... But who knows, you might find a piece of it anywhere.... as far as anyone knows, it isn't intact and is only found in bits and pieces of a once roaring river..
I've seen pieces of it near Barstow, Cal in the late 1960's... and what I mined on in Oregon... other than that, I haven't personally seen any other parts of the "Blue lead"...
I hope you do have a small part of it, because if you do, you'll probably find it very, very rich indeed...
Good luck to you... what you have is a very pretty blue color, for sure...
Klondike