Mineraloid (Human Made Geological Specimen)

Porphyritic Basalt (with Amygdales)

Amygdaloidal Porphyritic Basalt

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Porphyritic Basalt (or Andesite) Pebble

Porphyritic Mafic Volcanic Rock

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Jasper (likely a variety of Brecciated Jasper or a patterned variety)

Silicon dioxide (SiO2)

Veined Pebble (likely a Quartz-Veined Pebble)

Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)

Sandstone

Arenite (primarily SiO2 with trace Fe2O3)

Slickenside

Tectonic Fault Scarp Surface

Yellow Chert

Sedimentary cryptocrystalline quartz (SiO2)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Matrix

Quartz / Quartzite

Silicon Dioxide (SiO2)

Sandstone (likely Arkosic)

Clastic Sedimentary Rock (primarily SiO2 with Feldspar)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Basalt with Quartz/Calcite Veins

Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)

Rough Quartz (with Feldspar inclusions)

Silicon Dioxide (SiO2)

Obsidian

Amorphous volcanic glass (primarily SiO2)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Rough Garnet (likely Almandine or Pyrope)

Garnet group; Almandine Fe3Al2(SiO4)3 or Pyrope Mg3Al2(SiO4)3

Porphyritic Basalt (with Lath-like Phenocrysts)

Porphyritic Basalt

Septarian Nodule (Dragon Stone)

Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Limonite Concretion (Ironstone)

Limonite (FeO(OH)·nH2O) with Goethite and Hematite

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Goethite/Hematite shell with Sandstone core)

Moqui Marble (Iron Concretion)

Iron Oxide Concretion (Goethite/Hematite Cemented Sandstone)

Pink Granite

Phaneritic intrusive felsic igneous rock

Ferruginous Sandstone (Ironstone)

Sedimentary rock with high iron oxide content (Fe2O3 / FeO(OH))

Epidote in Matrix (likely Amphibolite or Gneiss)

Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Metamorphic Matrix

Almandine Garnet

Almandine (Fe3Al2(SiO4)3)

Banded Iron Formation (BIF)

Banded Iron Formation (SiO2 + Fe2O3/Fe3O4)

Ferruginous Quartz on Ironstone

Silicon Dioxide (SiO2) with Hematite (Fe2O3)

Sandstone

Quartz Arenite (a type of sandstone composed of more than 90% quartz)

Conglomerate

Conglomerate (clastic sedimentary rock)

Nephrite Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)

Weathered Volcanic Rock (possibly Rhyolite or Andesite Pebble)

Volcanic rock (e.g., Rhyolite or Andesite, specific identification would require thin section analysis or chemical assay). Mineral composition: Primarily feldspars (orthoclase and/or plagioclase), quartz (in rhyolite), micas, amphiboles, and sometimes pyroxenes.

Botryoidal Aragonite (Cave Popcorn)

Aragonite (Calcium Carbonate, CaCO3)

Gastropod Internal Mold (Steinkern)

Class Gastropoda fossil mold (Phylum Mollusca)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Red Sandstone

Arenite (with Iron Oxide)

Scoria (Vesicular Basalt)

Scoria (Extrusive Mafic Igneous Rock)