The most southern portion of Cury forms a part of Goonhilly Downs,
which rest on a dark and rather hard serpentine, spangled with small
scales of diallage, and having asbestos, indurated talc, and other
magnesian minerals, lining the joints, by which this rock may be
easily split. The remainder of the parish is composed of compact and
schistose hornblend rocks, of the calcareous series, which are best
exposed on the shores of Gunwalloe.