 |
|
|
 |
|
|
Mineral Characteristics - Colors and Shapes
|
|
|
|
|
Mineral
|
Characteristic colors
|
Shape
|
Observations
|
|
|
|
Graphite
|
Grey, shiny
|
Flakes
|
remain on surface
|
|
Micas
|
White, yellow, black, brilliant
|
|
Molybdenite
|
Light grey, brilliant
|
Flakes
|
particularly after crushing
|
|
Speculante
|
Brilliant, black
|
Fine flakes
|
|
Sulphides (pyrite, chalcopyrite, pyrrhotite, etc)
|
Grey, yellow, metallic
|
Dust
|
|
Gold
|
Metallic, golden yellow
|
Fine flakes
|
|
|
2. Minerals forming white ring
|
|
Quartz
|
White, grey mat or shiny
|
Grain, often fragments with crystaline faces
|
Largest are included in the next category
|
|
Feldspar
|
White, pale yellow, pink
|
|
Calcite
|
White, pale yellow, grey
|
|
Beryl
|
White, pale yellow, emerald green
|
|
3. Outside part of black tongue (black sand)
|
|
Fluorite
|
Violet, green
|
Grains
|
Largest identical with next category
|
|
Andalusite
|
White, greyish
|
Fine elongated prisms
|
|
Apatite
|
Grey, light pinky-brown
|
Fragments of hexagonal prisms
|
|
Tourmaline
|
Black, dark green
|
Fragments of prisms with triangular section started longitudinally
|
|
Amphiboles
|
Dirty green, black green
|
Grains, cleavage 124o
|
|
Pytosenes
|
Dirty green, black green
|
Grains, cleavage 90o approx
|
|
Pisolites
|
Rust brown
|
Grains, more or less spherical
|
|
4. Inside part of black tongue (black sand)
|
|
Ceylonite
|
Green
|
Grains of ten octahedron
|
Maybe attracted to magnet.
Particular refraction in water.
|
|
Topaz
|
Colorless, light green
|
Elongated, striated prisms
|
|
Kyanite
|
Pearly white, shimmering blue
|
Fragments, flattened prisms
|
|
Corundum
|
Light yellow, light grey
|
Grains
|
|
Sphene
|
Pinky grey
|
|
Epidote
|
Yellowy green
|
Grains, prism fragments
|
|
Staurolite
|
Dirty brown
|
Fragment, orthorhombic prisms
|
|
Olivine
|
Olive green
|
Grains, rounded
|
|
Garnets
|
White, mauve, red-brown
|
Grains, spherical with many faces
|
|
Specularite
|
Brilliant black
|
Grains, flake shaped
|
|
Ilminite
|
Purpley-black
|
|
Magnetite
|
Brownish black
|
Grains, octahedrons
|
|
Diamond
|
White, grey
|
Octahedrons, sometimes with curved edges, cubes
|
|
Zitcon
|
Grey, colorless, yellow, red
|
Grains, tetragonal prisms
|
|
Rutde
|
Metallic grey brown
|
Fragments, prisms with cleavages
|
|
Scheelite
|
Yellowish grey
|
Grains
|
|
Monazite
|
Dull orange brown
|
Fragments, fine prisms
|
|
5. Bottom of pan
|
|
Wolfram
|
Black
|
Grains, fragments, prisms
|
Constant intensity of color and shine when lit from an angle *
|
|
Chromite
|
Black
|
Grains, octahedrons
|
|
Cassiterite
|
Yellow, dark brown, black
|
Grains, sometimes cleavages
|
|
Columbo-Lantalite
|
Dull, dark brown
|
|
Phortanite
|
Black
|
Grains, cubes
|
|
Native copper
|
Pink-red with metallic shine
|
Grains, specks, flakes
|
|
Gold
|
Gold-yellow, with metallic shine
|
Grains, spots
|
|
Platinum
|
Grey with metallic shine
|
|
|
|
|
* Detail allowing native gold to be distinguished from some metallic sulphides, particularly of chalcopyrite, the grains of which are not shiny from some directions.
|
|
|
|
