Cleavage - the tendency of a mineral to break in certain preferred directions along a smooth surface

Color - characteristic color of certain minerals that distinguishes them from other minerals; sulfur is yellow

Crystal shape - natural configuration taken by the mineral as the crystal forms

Form - the general shape of the mineral; is it a single crystal, a group of small crystals, or a dense mass

Fracture - the way a mineral naturally breaks other than along a flat, cleavage plane

Hardness - measure of the mineral surface's resistance to abrasion; see Moh's Scale of Hardness

Luster - if a mineral looks like a metal, regardless of its color, it has a metallic luster; nonmetallic luster is dull, pearly, silky, glassy, or brilliant, or transparent

Specific Gravity - ratio of a mineral's mass to the mass of an equal volume of water (the higher the specific gravity, the heavier the mineral is); the specific gravity of most nonmetals is lower than 4

Streak - the color of a mineral in a finely powdered form; streak can be found by scratching a mineral against an unglazed tile

Striations - narrow lines that cross certain mineral surfaces

Unique Properties - Examples: taste (halite tastes salty), sulfur (smell), sound (jade produces a bell-like ring when tapped), chemical reaction