Crochet Afghans...

I came across this lovely afghan while out 'thrifting' over in Rathdrum, ID...
I washed & dried it and it fluffed (and felted) up ever so nice!
I started to think,,, that this is possibly crocheted from a natural fiber as opposed to an acrylic one...
I took some cast off fibers, and lit a match and the fibers burned & singed... not beaded/ melted so now the question is,,, what type of fiber? wool?, alpaca? or bamboo? or?
I do know that it is snuggle soft and warm and very heavy... and will go great in our larger vintage trailer.,,, that is, if I can part with it... lol!