Man Made Material (Metal)

Diamond

Diamond (C)

Chert (often called Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Sandstone (Siltstone/Mudstone variety)

Ferruginous Sandstone (composed primarily of Quartz with Hematite cementation)

Obsidian

Volcanic Glass (SiO2)

Red Sandstone

Arenite (primarily Quartz and Feldspar with Iron Oxide cement)

Diorite

Phaneritic Intermediate Plutonic Rock (Diorite)

Quartz (Common or Milky)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Ironstone Concretion / Goethite-Hematite Nodule

Goethite/Hematite (α-FeO(OH) / Fe2O3)

Quartzite

Quartzite (Primary mineral: SiO2)

Quartzite

Quartzite (primarily SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Green Aventurine

Silicon Dioxide with Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Chert (White/Gray variety)

Chert (SiO2)

Schist

Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)

Ferruginous Conglomerate

Ferruginous Conglomerate (Clastic Sedimentary Rock)

Olivine in Basalt (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite

Quartzite (primarily SiO2)

Diorite

Intrusive Igneous Rock (Intermediate Composition)

Yellow Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Quartzite

Quartzite (primarily SiO2)

Chert (specifically Gray/Black Chert)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Olivine (Peridot in gem form)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Shale (with Iron Oxide staining)

Fissile Mudstone (primarily Quartz and Clay minerals)

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Red Shale

Fissile Siliciclastic Sedimentary Rock

Granite River Pebble

Phaneritic Felsic Igneous Rock (Granite)

Biotite Schist

Biotite Mica Schist [K(Mg,Fe)3AlSi3O10(OH,F)2]

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Ferruginous Quartz (Agatized/Iron-stained Quartzite)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Chert (Iron-stained)

Chert (SiO2)

Ferruginous Sandstone

Arenite with Iron-Oxide cement (primarily Fe2O3 • nH2O)

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Red Jasper

Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Fulonite (Fulgurite-like)

Fulgurite (SiO2 fused silica/lechatelierite)