I haven't climbed it but according to the beckey book, and looking from Independence Ridge, it is minor rock scramble. The book concurs with what others have stated about the approach, which is from behind the ranger cabin the peak isn't too far of a climb. You can also access the trail to Redstone Peak from FS 74. You should be able to get a map from Enumclaw. This shortcut will make it about 2-3 miles from the car to the cabin and then to the peak from there. Sorry I don't about what type of rock it is.