Part 4

A. Can be scratched by a fingernail Amphibole asbestos White Made up of 1-2½ slender, flexible fibers that can be pulled apart Cerargyrite Shiny white or Appears waxy; 1-1½ gray knife cuts it smoothly; turns violet brown to black when exposed to light Gypsum White Soft; occurs as 2 crystals or as fibrous, granular, compact, or earthy masses Sulfur White or pale Will burn with a 1½-2½ yellow blue flame; commonly found as crystals, crusts, or grains Talc White Knife cuts it 1 smoothly; feels soapy or greasy; splits into thin flakes B. Cannot be scratched by a fingernail but can be scratched by a copper penny Amphibole asbestos White Made up of 1-2½ slender, flexible fibers that can be pulled apart Anhydrite White Commonly occurs 3-3½ as sugary-looking masses Calcite White Dilute 3 hydrochloric acid fizzes on calcite; perfect cleavage in 3 directions gives rhomb-shaped fragments Celestite White Crystals commonly 3-3½ prism-shaped or flat-looking; some cleavage fragments are flat and slab-like Halite White Salty taste; 2½ dissolves in water; cube-shaped cleavage fragments Sulfur White or pale Will burn with a 1½-2½ yellow blue flame; commonly found as crystals, crusts, or grains C. Cannot be scratched by a copper penny but can be scratched by an ordinary pocket knife Anhydrite White Commonly occurs 3-3½ as sugary-looking masses Celestite White Crystals commonly 3-3½ prism-shaped or flat-looking; some cleavage fragments are flat and slab-like Dolomite White Commonly occurs 3½-4 as granular masses and as rhomb-shaped crystals; dilute hydrochloric acid may fizz slightly on dolomite Opal White Curved, 5-6 conchoidal fracture; may appear glassy, greasy, resinous, or dull D. Cannot be scratched by an ordinary pocket knife but can be scratched by quartz Feldspar White Glassy or pearly 6 luster; good cleavage in 2 directions that meet at an angle of 90° or near 90°; common in granite and pegmatite rocks Opal White Curved, 5-6 conchoidal fracture; may appear glassy, greasy, resinous, or dull Quartz White Curved conchoidal 7 fracture; occurs as chert and chalcedony

8. NONMETALLIC luster, YELLOW color

A. Can be scratched by a fingernail Carnotite Yellow Bright canary 2 yellow or lemon yellow; radioactive; occurs as crusts and powdery masses Gypsum White Yellowish; soft; 2 occurs as crystals or as fibrous, granular, compact or earthy masses Limonite Rusty yellowish Brownish-yellow 1+ brown color; may be soft and earthy Muscovite (white White Light colored; 2-2½ mica) splits into thin, flat, transparent sheets that will bend without breaking Sulfur White or pale Will burn with a 1½-2½ yellow blue flame; commonly found as crystals, crusts, or grains Uranophane Light yellow to Yellow to 2-3 light yellow yellow-orange orange color; radioactive B. Cannot be scratched by a fingernail but can be scratched by a copper penny Barite White Rather heavy; 3-3½ cleavage fragments may be flat and slab-like Calcite White Yellowish; dilute 3 hydrochloric acid fizzes on calcite; perfect cleavage in 3 directions gives rhomb-shaped fragments Muscovite (white White Light colored; 2-2½ mica) splits into thin, flat, transparent sheets that will bend without breaking Sulfur White or pale Will burn with a 1½-2½ yellow blue flame; commonly found as crystals, crusts, or grains Uranophane Light yellow to Yellow to 2-3 light yellow yellow-orange orange color; radioactive C. Cannot be scratched by a copper penny but can be scratched by an ordinary pocket knife Barite White Rather heavy; 3-3½ cleavage fragments may be flat and slab-like Opal White Curved, 5-6 conchoidal fracture; may appear glassy, greasy, resinous, or dull D. Cannot be scratched by an ordinary pocket knife but can be scratched by quartz Feldspar White Glassy or pearly 6 luster; good cleavage in 2 directions that meet at an angle of 90° or near 90° Garnet White Commonly occurs 6½-7 as crystals Opal White Curved, 5-6 conchoidal fracture; may appear glassy, greasy, resinous, or dull Quartz White Curved conchoidal 7 fracture; brownish-yellow _smoky_ quartz crystals commonly 6-sided prisms with pyramid-like ends; _chalcedony_ and _jasper_ may be a shade of yellow, too

9. NONMETALLIC luster, BROWN color

A. Can be scratched by a fingernail Gypsum White Brownish; soft; 2 occurs as crystals or as fibrous, granular, compact or earthy masses Limonite Rusty yellowish May be soft and 1+ brown earthy Muscovite (white White Light colored; 2-2½ mica) splits into thin, flat, transparent sheets that will bend without breaking Sulfur White or pale Will burn with a 1½-2½ yellow blue flame; commonly found as crystals, crusts, or grains B. Cannot be scratched by a fingernail but can be scratched by a copper penny Barite White Rather heavy; 3-3½ cleavage fragments may be flat and slab-like Biotite (black mica) White Dark brown; 2½-3 splits into thin, flat sheets that will bend without breaking Calcite White Dilute 3 hydrochloric acid fizzes on calcite; perfect cleavage in 3 directions gives rhomb-shaped fragments Halite White Salty taste; 2½ dissolves in water; cube-shaped cleavage fragments Muscovite (white White Light colored; 2-2½ mica) splits into thin, flat, transparent sheets that will bend without breaking Sulfur White or pale Will burn with a 1½-2½ yellow blue flame; commonly found as crystals, crusts, or grains C. Cannot be scratched by a copper penny but can be scratched by an ordinary pocket knife Barite White Rather heavy; 3-3½ cleavage fragments may be flat and slab-like Dolomite White Commonly occurs 3½-4 as granular masses and as rhomb-shaped crystals; dilute hydrochloric acid may fizz slightly on dolomite Fluorite White Cleavage in 4 4 directions can give fragments that are shaped like octahedrons; crystals commonly cube-shaped D. Cannot be scratched by an ordinary pocket knife but can be scratched by quartz Cassiterite Pale brown, pale Brown, reddish 6-7 yellow, or white brown, or yellowish brown; heavy; dull to brilliant luster Feldspar White Glassy or pearly 6 luster; good cleavage in 2 directions that meet at an angle of 90° or near 90°; common in granite and pegmatite rocks Garnet White Commonly occurs 6½-7 as crystals Quartz White Curved conchoidal 7 fracture; brown _smoky_ quartz crystals commonly 6-sided prisms with pyramid-like ends; _chalcedony_, _chert_, and _jasper_ may be a shade brown, too Tourmaline White Dark brown 7-7½ variety is _dravite_; notice hardness, striations on crystals, and triangular cross section of some crystals E. Cannot be scratched by quartz Tourmaline White Dark brown 7-7½ variety is _dravite_; notice hardness, striations on crystals, and triangular cross section of some crystals

10. NONMETALLIC luster, BLACK color