Malachite stone

…a malachite stone. The stone is very dull, is there a way to
polish it?

Try very fine wet and dry sandoaper about 1200 grit to remove any
fine scratches. Then polish with tin oxide mixed to a paste with
water. You can apply this to a clean mop and to the stone. this
should bring it up a treat. Take it quietly (malachite is soft)
and do not let the stone get to hot. Best wishes Gerald.

opalsopalsopals*