Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)

Vesicular Basalt (Amygdaloidal)

Vesicular Basalt (Fe-Mg rich extrusive volcanic rock)

Petrified Wood

Silicified Wood (SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Sandstone (Calcareous Sandstone)

Calcareous Sandstone (primarily SiO2 with CaCO3 cement)

Graphite

Graphite (Native Carbon, C)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Granite Glacial Erratic

Intrusive Phaneritic Felsic Rock (Granite)

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Sandstone (with Iron concretions/staining)

Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)

Fossilized Coral

Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)

Chert (often called Flint in this variation)

Silicon dioxide (SiO2) - Microcrystalline quartz

Geode (Unopened)

Silica-rich Concretion (primarily SiO2)

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock - Arenite

Conglomerate

Conglomerate rock

Boxwork Quartz / Septarian Jasper

Boxwork (SiO2 with iron oxide inclusions)

Sandstone (likely Arkosic or Lithic Sandstone)

Arenite (SiO2 based with mineral inclusions)

Pink Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Rough Amber (likely Copal or immature Amber)

Organic gemstone / Succinite (if Baltic)

Thunderegg (specifically a Jasper/Agate-filled Geode nodule)

Silicon Dioxide (SiO2) within Rhyolitic Matrix

Milky Quartz

Silicon Dioxide (SiO2)

Diorite

Diorite (Intermediate intrusive igneous rock)

Sandstone (Ferruginous)

Clastic Sedimentary Rock (Litharenite)

Brown Jasper (Likely)

Jasper (Cryptocrystalline Silicon Dioxide - SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)

Red Sandstone

Arenite (primarily SiO2 with hematite/iron oxide coating)

Sandstone

Arenite (primarily SiO2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Biotite (Black Mica)

Biotite (K(Mg,Fe++)3AlSi3O10(OH,F)2)

Sandstone

Arenite (primarily Quartz, SiO2)

Garnet (likely Pyrope or Almandine)

Garnet Group (complex nesosilicate minerals, e.g., Pyrope Mg3Al2(SiO4)3, Almandine Fe3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3, Grossular Ca3Al2(SiO4)3, Andradite Ca3Fe2(SiO4)3, Uvarovite Ca3Cr2(SiO4)3). The vivid red color in the image strongly suggests Pyrope or Almandine.

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and Biotite)

Chrysocolla

Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·n(H2O)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Arenite

Sandstone (Fossiliferous)

Clastic Sedimentary Rock (primarily SiO2)

Hypersthene

Hypersthene (formula: (Mg,Fe)SiO3)

Chert (varieties: Flint or Chalcedony)

Microcrystalline Quartz (SiO2)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

Milky Quartz with Mica inclusions

Quartz (Silicon Dioxide, SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Amber

Succinite (a fossilized organic resin)