This Is Not A Rock Or Mineral

Amethyst Geode

Silicon Dioxide (SiO2) - Amethyst variety of Quartz

Green Aventurine

Quartz variety (SiO2 with inclusions)

White Jade / White Chalcedony

Nephrite Jade (Ca2(Mg,Fe)5Si8O22(OH)2) or Chalcedony (SiO2)

Sandstone

Sandstone (lithified sand)

Basalt (Crushed Stone Aggregate)

Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)

Quartzite River Rock with Dendrites

Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Michigan Float Copper

Native Copper (Cu)

Dolomite on Prehnite (Saddle-shaped Dolomite)

Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]

Sandstone (Cross-bedded Drill Core)

Clastic Sedimentary Rock (primarily SiO2)

Ironstone (with possible Hematite/Limonite coating)

Ironstone (Fe-rich sedimentary rock)

Diorite

Diorite (Intermediate intrusive igneous rock)

Granite

Granite (Phaneritic Quartz-Feldspar Igneous Rock)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (Brown variety / Common Jasper)

Microcrystalline Quartz (SiO2)

Granite Pebble

Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)

Conglomerate (River Rock)

Clastic sedimentary rock (primarily SiO2)

Banded Gneiss

Gneiss (complex metamorphic silicate rock)

River Cobble (likely Basalt or Rhyolite)

Extrusive Igneous Rock (Mafic or Intermediate)

Amethyst Geode (polished heart-cut)

Silicon Dioxide (SiO2) with iron impurities

Basalt with Magnetite inclusions

Basalt (Mafic silicate rock) potentially containing Magnetite (Fe3O4)

Red Scoria (Lava Rock)

Vesicular Basalt / Scoria

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (Clastic Sedimentary Rock)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2 with minor Fe2O3)

Quartz (specifically Clear Quartz with iron/hematite staining)

Silicon Dioxide (SiO2)

Obsidian

Obsidian (Volcanic Glass)

Granite

Phaneritic Felsic Igneous Rock

Amethyst

SiO2 (Silicon Dioxide)

Granite (with Orthoclase and Quartz)

Phaneritic Felsic Igneous Rock (KAlSi3O8 + SiO2)

Quartz Veined Basalt

Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)

River Siltstone Pebble

Siltstone (primarily composed of silica and clay minerals)

Mica Schist

Mica Schist (primarily Muscovite and Quartz)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Porphyritic Basalt (with Amygdales)

Amygdaloidal Porphyritic Basalt

Petrified Wood

Silicified Wood (primarily SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Serpentinite (Serpentine Rock)

Serpentinite is a rock composed of one or more serpentine group minerals, chiefly antigorite, chrysotile, and lizardite, with the general formula (Mg,Fe)3Si2O5(OH)4. Often includes other minerals like magnetite, talc, and chromite.

Moss Agate

Agate (Silicon Dioxide, SiO2) with dendritic inclusions

Labradorite (Larvikite variety)

Feldspar (Plagioclase series), (Na,Ca)(Si,Al)4O8

Scoria (Volcanic Rock)

Scoria (often basaltic scoria)