Sedimentary Or Igneous (Host Environment)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Granite Pebble

Granite (Felsic Plutonic Rock)

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chrysocolla

Hydrated copper phyllosilicate, Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)

Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Gold Nugget

Native Gold (Au)

Shale or Mudstone River Pebble

Argillaceous sedimentary rock

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Sandstone (Quartzite texture)

Arenite (SiO2 secondary)

Garnet Schist

Garnetiferous Micaceous Schist

Pyrite in Matrix (Fool's Gold)

Iron Sulfide (FeS2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Yellow Quartz (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Quartz (Milky Quartz vein fragment)

Silicon Dioxide (SiO2)

Copper-bearing Quartz (likely Chrysocolla or Malachite staining)

Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock

River Rock (likely Siltstone or fine-grained Sandstone)

Clastic Sedimentary Rock

Bull Quartz

Quartz (Silicon Dioxide - SiO2)

Pink Granite (Water-worn Pebble)

Felsic Intrusive Igneous Rock (Granite)

Granite Cobble

Granite (Felsic intrusive igneous rock)

Granite Pebble

Granite (Phaneritic intrusive igneous rock)

Ironstone Concretion (Coprolite-like)

Goethite/Hematite Siderite Spheroid (FeCO3 or FeO(OH))

Limonite Geode / Ironstone Concretion with Quartz

Limonite with Quartz (FeO(OH)·nH2O + SiO2)

Pyrite

Iron Disulfide (FeS2)

Gold Ore in Matrix

Native Gold (Au) in Quartz/Host Rock

Chert Geode with Quartz Druzy

Microcrystalline Quartz (SiO2) with macrocrystalline Quartz

Chalcedony (Agate/Carnelian variant)

Silicon Dioxide (SiO2)

Quartz with Mica inclusions (likely Schist or Gneiss host)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

Emerald

Beryl (Be₃Al₂(SiO₃)‑₆) with Chromium/Vanadium impurities

Hag Stone

Perforated Chert (Microcrystalline Silica, SiO2)

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Geode (Druzy)

Crystalline Silicon Dioxide (SiO2)

Basalt with Quartz/Calcite Veins

Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt with Quartz/Feldspar Inclusions

Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining

Red Scoria (Lava Rock)

Scoria (Vesicular Basalt)

Granite Pebble

Intrusive Magmatic Granite (Quartz, Feldspar, Mica)

Granite (River Cobble)

Phaneritic Plutonic Felsic Rock (Granite)