Man Made Material, Not A Natural Rock Or Mineral Specimen

Sandstone

Arenite (Clastic Sedimentary Rock)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Quartz-veined Siltstone

Siltstone with Quartz (SiO2) veins

Heliotrope (Bloodstone)

Silicon dioxide (SiO2) with inclusions

Jasper with Quartz Veining

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone with Iron Concretion

Arenite with Limonite/Goethite Concretion

Tree Agate

Dendritic Chalcedony (SiO2)

Caliche (also known as hardpan, calcrete, kankar)

Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of iron)

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Red Sandstone (Arkose)

Clastic Sedimentary Rock (Lithic Arkose)

Pyrite in Shale

Iron Sulfide (FeS2) in Sedimentary Matrix

Epidote

Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Orange Quartzite / Carnelian Agate

Silicon Dioxide (SiO2)

Sandstone Beach Pebble

Clastic sedimentary rock (SiO2 with iron oxide cement)

Schist (Kyanite Schist)

Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)

Sandstone (Red)

Arenite (primarily Quartz, SiO2, with Iron Oxide cement)

Milky Quartz

Silicon Dioxide (SiO2)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Volcanic Rock)

Sandstone

Arenite (primarily composed of SiO2 - Silicon Dioxide)

Sandstone (Quartzose Pebble)

Clastic sedimentary rock (primarily SiO2)

Banded Agate (Orca Agate)

Silicon Dioxide (SiO2) - Chalcedony variety

Milky Quartz

Silicon Dioxide (SiO2)

Yellow Quartz / Quartz Pebble

Silicon Dioxide (SiO2)

Metaconglomerate

Metaconglomerate (Quartzite conglomerate)

Sandstone

Sandstone (principally SiO2)

Conglomerate

Conglomerate (Clastic Sedimentary Rock)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Druzy Quartz

Silicon Dioxide (SiO2)

Amethyst on Agate/Basalt Matrix

Silicon Dioxide (SiO2) with iron impurities

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Sandstone (specifically Red Sandstone)

Arenite (primarily Quartz, SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Tree Agate

Silicon Dioxide (SiO2) - Dendritic Agate/Chalcedony

Lava Rock (Basalt)

Basalt (extrusive igneous rock)

Basalt River Cobble

Basalt (Aphanitic Mafic Volcanic Rock)

Quartz Geode (partially formed)

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite / KAl2(AlSi3O10)(OH)2

Lapis Lazuli

Lazurite-dominant Metamorphic Rock (complex aluminosilicate)

Citrine or Yellow Quartz

Silicon Dioxide (SiO2) with iron impurities