Petrified wood is actually rock formed by the gradual replacement of wood by minerals. Mineral matter is deposited in and around cells of wood. Crystals or grains of silica are the mineral quartz, but the silica in petrified is so fine that you can't see the grains even with a microscope. Rock composed of cryptocrystalline quartz is called chert. So it ranges from white, to cream, to red, to black, to yellow.
Red chert is jasper.
The silica making petrified wood came from the volcanic ash. Water passing through the ash dissolved the silica, and then it precipitated in the wood.