Rock-forming mineral consisting of aluminium silicates that represents around 60 per cent of our planets crust (8)
I believe the answer is:
feldspar
(Other definitions for feldspar that I've seen before include "Raw material used in glass-making, ceramics etc - red flaps (anag)" , "Common mineral" , "Rock-forming mineral" , "Abundant mineral" , "Large wading bird" .)