is a metallic. Very dense, gray, shiny, sulfide mineral. PbS

Galena

Leaves a black streak, metallic group, oxide mineral, Fe3O4 (is magnetic)

Magnetite

Gray streak, blackish gray, metallic group, native element (you can write with it) C

Graphite

red and black, leaves a red streak, metallic group, oxide mineral. Fe203

Hematite

black with gold, metallic group, black streak, fools gold, sulfide mineral FeS2

Pyrite

Silicate mineral, Dark, red, glassy, non-metallic group, brittle Fe, Mg, Ca, Al

Garnet

Salty Taste, not very dense, clear in color, cubic cleavage, halite mineral NaCl

Halite

scratch with fingernail, non-metallic, light, sulfate mineral, soft, CaS04 2H20

Gypsum

Reacts with HCL, white, brown, clear, perfect cleavage, no 90 angles, carbonate mineral CaCO3

Calcite

Purples, blues, yellow, clear, non-metallic, Illinois state mineral, soft, cleavage, halide mineral CaF2

Fluorite

Silicate mineral, always olive green, isolated tetrahedral, no cleavage, hard, non-metallic group MgFe

Olivine

dark mica, silicate, cleaves into thin sheets, non-metallic group, KMgFeAl,

Biotite Mica

light mica, silicate, breaks into thin sheets, cleavage, soft, non-metallic group, Al

muscovite mica

pink and salmon colored, planes at 90, milky, silicate, non-metallic group, K Al

K Feldspar

SiO2, silicate mineral, non-metallic group, pink, purple, brown, clear, breaks into sharp edges, crystals, no cleavage, hard

Quartz

phaneritic, silicic, felsic, light colored, Quartz. K-feldspar

Granite

crystals not visible, (aphanitic or porphyritic) silicic, felsic, light colored, quarts, K-feldspar

Rhyolite

Intermediate, gray, phaneritic, K-feldspar, plagioclase feldspar, Biotite, quartz, augite

Diorite

Intermediate, gray, porphyritic, or aphanitic, K-feldspar, plagioclase feldspar, biotite, quartz

Andesite

Mafic, dark brown or black, phaneritic, Ca-plagioclase, Olivine,

Gabbro

Mafic, dark brown or black, Porphyritic or aphanitic, Ca-plagioclase, Olivine

Basalt

Solid Glass, no crystals present

Obsidian

Vernacular Glass, gray to tan

Pumice

Clastic , coarse grained, rounded clasts,

Conglomerate

Coarse grained, angular clasts

Breccia

Medium grained, mostly quartz

Quartz Sandstone

Medium grained, feldspar, Quartz,

Arkosic Sandstone

Dirty sandstone, medium grained, quartz, rock fragments,

Graywacke

Very fine grained, very fine grained, clay minerals, and sometimes quartz

Shale

swamp environments, decomposed plant material, black often shiny, organic carbon

Coal

calcite

Coquina

Halite

Rock Salt

SiO2

Chert

alternating light and dark bands
light bands: quartz and feldspar
Dark bands: hornblende, augite, garnet, biotite, etc.

Gneiss

Sheet-like grains; scaly, "shitose" texture. Sparkly or shiny appearance. ("Shiny Schist")
minerals: biotite, muscovite, chlorite. Minor amounts of quartz, or dark silicate minerals

Schist

microscopic flakes of mica create a sheen (slight reflective surface)

Phyllite

parallel orientation of of mica flakes created "slatey cleavage" planes of weakness

Slate

very hard (scratches glass). visible grains of quartz

Quartzite