14 Mineral Properties 2. Luster – The way a minerals shines A. Metallic Luster– Looks like a metal
15 Mineral Properties 2. Luster – The way a minerals shines B. Nonmetallic Luster– Does not look like a metal
16 Mineral Properties 3. Hardness – A minerals resistance to being scratchedGlass PlateHardness = 5.56. FeldsparFingernail = 2.5
17 Mineral Properties 4. Cleavage/Fracture Cleavage occurs when minerals break along planes of weak bonds.Results in smooth, flat surfacesWhen a mineral with cleavage is broken, the pieces look similar
18 Mineral Properties 4. Cleavage/Fracture Fracture – breakage not on cleavage planesLike broken glass – no two pieces are the same
19 Mineral Properties 5. Streak – The color of a mineral in powdered form Tested by rubbing mineral on a streak plate.