MT1: Minerals with Metallic Luster or Dull (Tarnished) Metallic Luster
Hardness |
Streak |
Cleavage |
Other |
Mineral |
< 5.5 (does not scratch glass) |
Black, green-black, brown-black, or gray |
One (possibly visible) |
Gray to black in color; dull luster; greasy feel |
Graphite C |
Three |
Silvery gray in color; cubic crystals are common |
Galena PbS |
||
None |
Brown to brownish black in color; submetallic luster common, weakly magnetic |
Chromite FeCr2O4 |
||
None |
Golden yellow to greenish yellow in color; massive |
Chalcopyrite CuFeS2 |
||
Yellow-Brown |
None |
Dark brown to black in color; massive or rounded forms with fiberous layers |
Geothite FeO(OH) |
|
Copper-red |
None |
Copper to brown in color but may have a green coating; malleable |
Native Copper Cu |
|
>5.5 (scratches glass) |
Black or Green-black |
None |
Brass-yellow in color; massive or as crystals |
Pyrite FeS2 |
Black |
None |
Dark gray to black in color; dull luster |
Magnetite Fe3O4 |
|
Red-brown |
None |
Steel gray to dull red in color; massive or may have tiny flakes |
Hematite Fe2O3 |
