Organic (Often Found By Beachcombers)

Chalcedony (Botryoidal Agate)

Silicon Dioxide (SiO2)

Chert (specifically Flint or Common Opal/Chalcedony mix)

Microcrystalline Quartz (SiO2)

Banded Calcite (Mexican Onyx)

Calcium Carbonate (CaCO3)

Unakite (Epidote with Quartz and Feldspar)

Unakite (Metasomatized Granitic Rock)

Geode (Unopened)

Silicon Dioxide (SiO2) in sedimentary vugs

Carnelian

Carnelian (SiO2)

Unakite

Epidotized Granite

Granite

Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8, and Mica)

Olivine (Peridot when gem-quality)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Barite (Desert Rose or Cockscomb variety)

Barium Sulfate (BaSO4)

Blue Chalcedony

Silicon Dioxide (SiO2)

Carnelian

SiO2 (Chalcedony with iron oxide impurities)

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Chalcedony (Moonstone-like Agate)

Silicon Dioxide (SiO₂)

Rhodonite

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Nephrite Jade

Ca2(Mg, Fe)5Si8O22(OH)2 (Tremolite-Actinolite series)

Fluorite

Calcium Fluoride (CaF2)

Chert (Flint) Nodule

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Olivine (Peridot)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Clear Quartz

Silicon Dioxide (SiO2)

Botryoidal Hematite (Kidney Ore)

Iron(III) oxide (Fe2O3)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Fossilized Shark Tooth

Otodus obliquus (Mackerel Shark)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Iron-stained Quartz (with Limonite/Hematite)

Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)

Quartzite

Quartzite (SiO2)

Quartzite Pebble

Quartzite (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Sandstone Concretion

Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)

Granite

Phaneritic plutonic rock (Felsic)

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2), a variety of Actinolite-Tremolite

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Chert (Yellow/Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Satin Spar (often marketed as Selenite)

Fibrous Gypsum (CaSO4·2H2O)

Milky Quartz

Silicon Dioxide (SiO2)