Geology

recognition exam

gold

gold

metal

sulfur

non-metal

graphite

non-metal

Pyrite

sulfide crystal: diamond - коцкички

Marcasite

sulfide crystal: rhombic - локумчиња

Galena

sulfide crystal: diamond - коцкички

Pyrrhotite

sulfide

Chalcopyrite

sulfide

fluorite

halide

halite

halide

magnetite

oxide crystal: diamond color: gray, black with brownish tint in reflected sun Luster: Metallic Streak: Black Cleavage: Indistinct, parting on, very good magnetic strongly attracted to magnets

hematite

oxide

silica

oxide

chalcedony

oxide

opal

oxide

cassiterite

oxide

lepidocrockite

goethite (limonite)

manganomelane

calcite

carbonate vitreous luster - resembles the luster of glass usually white, but also colorless, gray, red, green, blue, yellow, brown, orange white streak basic soft forms bubbles with acid perfect cleavage - cleave without leaving any rough surfaces; a full, smooth plane is formed where the crystal broke

clay shale

color: black, grey, but brown, off-white, red, green, and blue are common soft - can be split easily into fragile slabs acid test doesn't help, some shales will react with acid and others won’t Fine-grained – Grains are too small to see with the naked eye

claystone

may be any color, but is generally greenish gray to grayish black relatively soft

conglomerate

has little pebbles in it

feldspar

have cleavage hard: can't make scratch acid: nothing happens

gabbro

dark colored it's hard, it can scratch glass gabbro is made out of bigger pieces then basalt, which has smaller ones can be confused with basalt, the difference is that gabbro has crystals in it gabbro is a coarse grained rock, basalt is a fine grained rock

glauconite

light green streak Color: Blue green, green, yellow green can be confused with chlorite

granite

grainy structure hard identifying - look for rocks with crystals. Look for shiny, flat surfaces within the rock—these are the crystal faces

graywacke

greenish-gray color

gypsum

linear orthogneis

loess

lydite

lydite

limestone

makes bubbles with acid limestone shouldn't be gray granular texture color: It can be yellow, white, or gray limestone is usually gray, but it may also be white, yellow or brown. It is a soft rock and is easily scratched

marleystone

lymestone

mica shist

paleorhyolite

paragneis

quartzitic sandstone

quartz

no cleavage Color: Colorless through various colors to black Luster: Vitreous – waxy to dull when massive Streak: White

sandstone

sandstone

stromactitic magmatite

syenite

texture: granular, and these rocks differ from granite only by the absence or scarcity of quartz color: pale colored, grey and pink fractional crystallization

trachyte

travertine

haematite

color: red crystal: rhombic

fluorite

halide

limonite

Luster: Earthy Color: Various shades of brown and yellow Streak: Yellowish brown Cleavage: Absent

aragonite

Color: White, red, yellow, orange, green, purple, grey, blue and brown Cleavage: Distinct, imperfect, good Luster: Vitreous, resinous on fracture surfaces Streak: White - unrecognizable

magnesite

color: Colorless, white, pale yellow, pale brown, faintly pink, lilac-rose, grayish, yellowish, brownish, rarely colorless cleavage: perfect luster: Vitreous but also dull, earthy, chalky, rarely vitreous streak: white can be hard to identify and is often confused with howlite makes bubbles with acid

siderite

dolomite

anhydrite

apatite

olivine

garnet

tourmaline

muscovite

color: white, transparent

biotite

color: black

chlorite

color: green like

kaolinite

phyllosilicate

montmorillonite

phyllosilicate

illite

serpentine

Analcime

tectosilicates Color: White, colorless, gray, pink, greenish, yellowish Cleavage: Very poor luster: vitreous

Leucite

tectosilicates Color: White to grey White streak vitreous luster cleavage: very poor