He found that all minerals could scratch the mineral talc, so it must be very soft.
(it; must be; very soft) (He; found; that all minerals could scratch the mineral talc, so it must be very soft) Context(He found,List([0, 8))):(all minerals; could scratch; the mineral talc)
He found,List([0, 8))
it He all minerals
must be found could scratch
very soft
that all minerals could scratch the mineral talc, so it must be very soft
the mineral talc