Metamorphic Rock (Specifically A Rock Composed Of Minerals)

Pyrite (Iron Pyrites)

Iron Sulfide (FeS2)

Quartzite

Quartzite (SiO2)

Chert (specifically Flint or Dark Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz (Milky/Clear Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky or Clear variety)

Silicon Dioxide (SiO2)

Geode (unopened)

Chert / Chalcedony Geode (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Unakite

Unakite (Epidotized Granite)

Unakite

Unakite (altered granitic rock: SiO2 + Ca2(Al,Fe)3(SiO4)3(OH))

Unakite

Epidotized Granite (Fe, Ca, Al silicate + KAlSi3O8)

Serpentine

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive volcanic rock)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartzite Pebble

Quartzite (primarily SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Ammonite Fossil

Ammonoidea (subclass)

Chert Nodule

Microcrystalline Silica (SiO2)

Chert (specifically Yellow or River Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Amygdaloidal Rhyolite

Amygdaloidal felsic extrusive rock

Amygdaloidal Basalt with Zeolite/Quartz Infill

Amygdaloidal Basalt (Host: (Mg,Fe)2SiO4 / CaAl2Si2O8; Infill: SiO2 or Na2Al2Si3O10·2H2O)

Schist

Schist (primarily mica-schist)

Sandstone

Arenite (SiO2 dominant)

Unakite

Epidotized Granite

Emerald In Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Diorite (Salt and Pepper Rock)

Diorite

Quartz (Milky Quartz)

Silicon Dioxide (SiO₂)

Quartzite with Iron Mineral Banding

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) staining

Conglomerate

Conglomerate (clastic sedimentary rock)

Granite Pebble (Weathered)

Phaneritic Felsic Igneous Rock

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Chalcedony (Agate/Jasper mix in host rock)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Sandstone (likely Ferruginous)

Sandstone (SiO2 with iron oxides)

Green Jasper (Heliotrope / Bloodstone variety)

Silicon Dioxide (SiO₂)

Serpentine (Serpentinite)

Antigorite, Lizardite, and Chrysotile: (Mg,Fe)3Si2O5(OH)4

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Sandstone Geode (Unbroken)

Siliciclastic sedimentary rock (primarily Quartz)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)