Mineral Like Byproduct (Often Mistaken For Igneous Rock Or Meteorite)

Labradorite (Larvikite variety)

Feldspar (Plagioclase series), (Na,Ca)(Si,Al)4O8

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Gneiss (specifically Banded Gneiss)

Gneiss

Yellow Quartz (Citrine/Quartzite Pebble)

Silicon Dioxide (SiO2)

Porphyritic Andesite (often called Chinese Writing Stone)

Porphyritic Basaltic Andesite with Feldspar Phenocrysts

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide staining)

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Limonite streaks)

Pyrite (Iron Pyrite)

Iron Disulfide (FeS2)

Milky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

Quartz (Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Fuchsite on Quartz

Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities

Diorite

Diorite (Intermediate Plutonic Rock)

Sandstone (Cross-bedded Drill Core)

Clastic Sedimentary Rock (primarily SiO2)

Sandstone (with biological crust)

Arenite (SiO2 based)

Granite

Granite (Felsic Plutonic Rock)

Rough Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Sandstone (Greywacke)

Arenite / Clastic Sedimentary Rock

Lapis Lazuli

Lazurite-rich metamorphic rock (approx. Na6Ca2(Al6Si6O24)(S,SO4,Cl)1,2)

Granatic Pegmatite

Pegmatitic Granite

Agate (specifically a small Chalcedony nodule)

Agate (Cryptocrystalline variety of Quartz, SiO2)

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Lapis Lazuli (Tumbled)

Lazurite-dominated contact metamorphic rock

Milky Quartz

Silicon Dioxide (SiO2)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Granodiorite

Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)

Banded Agate

Cryptocrystalline Quartz (SiO2)

Greenstone with Epidote or Quartz Vein

Epidiorite or Metabasalt (composed largely of Chlorite, Epidote, and Amphibole)

Agate

Silicon Dioxide (SiO2) - variety: Chalcedony

Red Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Magnetite

Iron(II,III) oxide (Fe3O4)

Sandstone (Quartzite-rich)

Clastic sedimentary rock (primarily SiO2)

Quartz (Citrine or Smoky variant)

Silicon Dioxide (SiO2)

Quartz (Crystal Point/Fragment)

Silicon Dioxide (SiO2)

Sandstone with Tafoni Weathering

Arenite (SiO2 based)

Basalt with Iron Oxidation

Extrusive Mafic Igneous Rock (composed of Plagioclase and Pyroxene)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock - Arenite

Sandstone Pebble

Arenite (primarily SiO2)