·
Hardness,
this is the minerals’ resistance to scratching or abrasion. One can identify
the hardness by scratching the unknown mineral and compare it with a known
hardness to determine which is harder.
·
Reaction
of the mineral to HCl (hydrochloric acid). You can do this by placing one small
drop of HCl on a sample mineral and observe if there are bubbles, this means a
reaction.