Sedimentary Rock (Possibly Composed Of Various Minerals)

Small rounded brown stone, likely weathered iron-rich rock

Indeterminate; possibly ferruginous sandstone, ironstone, or weathered basalt

Sandstone

Arenite (composed primarily of SiO2)

Sandstone Pebble

Sandstone (Quartzose/Feldspathic Sandstone)

Red Sandstone

Ferruginous Sandstone (SiO2 dominated with Fe2O3)

Jasper Pebble

Microcrystalline Quartz (SiO2)

Agate

Silicon Dioxide (Chalcedony), SiO2

Shale with Limonite/Hematite Staining

Argillaceous sedimentary rock with Iron Oxides (FeO(OH)·nH2O / Fe2O3)

Sandstone

Arenite (primarily SiO2)

Blue-gray chalcedony (likely common quartz/chert)

Microcrystalline quartz, SiO₂; possibly weathered chert or chalcedony

Sandstone

Sedimentary Clastic Rock

Likely rough quartz fragment

Quartz (SiO₂), possibly iron-stained or included quartz

Weathered iron-rich rock, possibly limonite-bearing basalt or ironstone

Uncertain; likely Fe-oxide/hydroxide–stained mafic rock (hematite Fe₂O₃, goethite FeO(OH), and silicates)

Concrete or artificial stone core sample

Artificial conglomerate

Iron-stained rock fragment (possibly limonite/goethite-rich)

Likely limonite, a mixture of hydrated iron oxides; may include goethite (α-FeO(OH))

Dark fine-grained rock, possibly basalt

Likely basalt; exact identification is uncertain from the low-resolution image.

Rough Diamond

Carbon (C)

Jasper

Jasper (Cryptocrystalline Quartz; SiO2)

Banded metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss, possibly amphibolite-bearing

Fossilized tooth fragment, possibly shark tooth

Fossilized vertebrate dental material, composed chiefly of hydroxyapatite

Sandstone

Sedimentary Rock (Quartz arenite)

Quartz-rich breccia (possibly silicified jasper or chalcedony breccia)

Silica breccia composed mainly of microcrystalline quartz (SiO₂), chalcedony, and possibly iron-oxide-stained quartz

Quartz

Quartz (SiO2 - Silicon Dioxide)

Foliated metamorphic rock (likely mica schist)

Mica schist, typically composed of quartz and mica (muscovite and/or biotite)

Sandstone (Iron-stained)

Arenite (primarily Quartz, SiO2)

Quartz Pebble

Silicon dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Sandstone (River Rock)

Arenite (composed primarily of SiO2)

Red Sandstone

Arenite (composed primarily of Quartz and Iron Oxide)

Granite

Felsic intrusive igneous rock

Sandstone

Sedimentary rock composed mainly of quartz sand grains

Sandstone

Arenite

Limonite/Goethite Concretion

Goethite (FeO(OH))

White Quartz

Silicon Dioxide (SiO2)

Banded Jasper (possibly "Picture Jasper")

Jasper (a microcrystalline variety of Quartz / Silicon Dioxide - SiO2)

Weathered iron-rich rock (possibly ironstone)

Likely ferruginous sandstone or ironstone; exact identification requires examination

Sandstone

Sedimentary Rock (Quartz Sandstone)

Likely sulfur-bearing rock (possibly native sulfur)

Native sulfur (S), though the image alone cannot confirm the specimen’s identity

Sandstone

Clastic sedimentary rock (Quartz arenite)

Weathered gneiss (likely)

Felsic banded gneiss, composed mainly of quartz and feldspar with mica

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Gneiss

Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)

Quartz-rich rock fragment, possibly chert or weathered quartz

Microcrystalline quartz (SiO₂), tentative identification