POLISHING JASPER
Jasper is much more troublesome to polish than agate because many varieties are "earthy" and porous and others contain hematite, which in itself is difficult to polish. If you are on a field trip, a good way to test for jasper is to wet it. If is absorbs the water and dries rapidly, throw it away. It will not polish. If it stays wet and does not dry right away, it contains a high amount of chalcedony and will take a good polish. Most jaspers polish well on leather with linde A, but good results can be obtained with tin oxide on either leather or felt. Always remember that a good fine sanding job is the secret of good polishing.
From Golden Spike News