yes it is some of the last really good rhyolite that i have,, works as good as the best danish flint ive ever knapped,,,i made a few type IV danish daggers out of the same stuff a few years back,,it stitches very good on the handles and pommel... wished i could get more ,but that rock came out of the ground at 30 feet deep.. ill never see anymore like that i guess... some ive got and a few points had spots and veins of white feldspar with iron pyrite crystals and veins running through it.. really awsome looking and very rare occurence in this type of stone... some knappers call it the king of stone..............james