Geo- Mineral Properties and Identification

Sphalerite (ZnS)

Sphalerite (ZnS)

-light brown streak -sulfur smell

Galena (PbS) -lead

-heavy palm weight -cubic cleavage -metallic dark grey streak

Gypsum -sheet rock

-scratch with fingernail -chalky white streak -layered sheets of cleavage

Hematite (Fe2O3) -iron = red

-metallic -auburn streak

Halite (NaCl) -salt

-90 degree cleavage -white chalky streak

Graphite (C)

-messy -pencil material

Flourite (CaF2)

-octahedral cleavage -color from inside out -varies colors

Magnetite (Fe3O4)

-magnetic

Kaolinite Clay

-extremely light palm-weight -powdery material

Hematite (Fe2O3) -iron = red

-red/orange streak -earthy luster

Calcite (CaCO3)

-lacks 90 degree cleavage -highly reactive to acid

Pyrite (FeS2)

-cubic cleavage -"fools gold"

Quartz (SiO2)

-scratches glass -no defined cleavage

Biotite

-flakes off -1 cleavage set

Feldspar (Orthoclase)

-barely scratches glass -salmon pink

Pyroxene (Augite)

-close to 90 degree cleavage -no streak -can be greenish

Olivine

-no cleavage -olive green color

Talc

-soapy feeling -pearly luster

Feldspar (Na- Plagioclase) -white color = Na

-striations present -no streak -reflects light

Muscovite

-flaky -1 cleavage set

Amphibole (Al2O3)

-tight planes -unique light pattern

Feldspar (Ca- Plagioclase) -deep black color = Ca

-striations on face -no streak

Quartz (SiO2)

-scratches glass -no cleavage

Garnet -can be green

-dodecahedron -no streak -red undertone