Sedimentary Rock (Possibly Composed Of Various Minerals)

Desert Varnish (on Sandstone)

Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)

Quartz-rich translucent pebble, possibly iron-stained quartz or chalcedony

Quartz (SiO₂), potentially microcrystalline quartz (chalcedony)

Chert / Quartzite

Silicon Dioxide (SiO2)

Dark volcanic rock, likely basalt

Basalt; fine-grained mafic silicate rock dominated by plagioclase and pyroxene, commonly with olivine

Dalmatian Jasper

Dalmatian Stone (Felsite with Arfvedsonite/Tourmaline)

Vesicular Basalt

Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Sandstone

Arenite

Mixed river stones and gravel

Polymictic alluvial clasts; individual pieces may include quartzite, granite, basalt, sandstone, limestone, and slate

Petrified Wood

Silicified wood (Quartz/Chalcedony/Opal)

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Ironstone Concretion / Goethite Nodules

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Sandstone

Sedimentary rock composed mainly of quartz sand

Chalcedony / Quartz Nodule (Agate Pebble)

Silicon Dioxide (SiO2)

Lapis Lazuli

Lazurite-rich metamorphic rock

Sandstone (Pebble)

Sandstone (principally SiO2 with iron oxide impurities)

Sandstone

Sandstone (SiO2 predominant)

Sandstone

Arenite (Clastic Sedimentary Rock)

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

Granite

Intrusive Igneous Rock

Sandstone

Sandstone (composed predominantly of Quartz, SiO2, with Feldspar and Clay minerals)

Lapis Lazuli

Lapis Lazuli (A complex rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli (Raw)

Lazurite-rich metamorphic rock; Na3Ca(Al3Si3O12)S

Lapis Lazuli

Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)

Sandstone (with secondary weathering/concretion)

Arenite (composed primarily of Quartz, SiO2)

Amygdaloidal Basalt with Secondary Minerals

Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)

Red Sandstone

Sandstone (Quartz Arenite / Arkose with Hematite cement)

Magnetite

Magnetite (Fe3O4)

Limestone with Fossil Inclusion

Calcium Carbonate (CaCO3)

Quartz (beads)

SiO2 (Silicon Dioxide)

Andesite

Intermediate Volcanic Rock (Andesite)

Sandstone

Arenite (SiO2 based with mineral cement)

Sandstone

Arenite (composed mainly of SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Weathered limestone or calcitic cave deposit

Calcite (CaCO₃), likely porous limestone/travertine

Limonite/Goethite Concretion

Goethite (FeO(OH))

Sandstone

Sandstone (SiO2 dominant)

Sandstone

Arenite (primarily SiO2)

Pyrite in Matrix

Iron Disulfide (FeS2)

Slate

Foliated Metamorphic Rock (composed of quartz, illite, and chlorite)