Sedimentary (Chemical)

Red Garnet

Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)

Cubic Zirconia

Zirconium Dioxide (ZrO2)

Gray Agate

Chalcedony (Silicon Dioxide, SiO2)

Agate

Cryptocrystalline Quartz (SiO2)

Amber Agate (Chalcedony)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Soapstone

Steatite (primarily Talc, Mg3Si4O10(OH)2)

Marble

Crystalline Limestone (mostly CaCO3 / Calcium Carbonate)

Garnet (likely Almandine or a blend)

Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.

Quartzite Cobble

Quartzite (SiO2)

River Cobble (Quartzite or Chert)

Metamorphic Quarzite (SiO2)

Orange Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartzite

Quartzite (primarily SiO2)

Gold Nugget

Native Gold (Au)

Quartz

Silicon Dioxide (SiO2)

Blue Quartzite

Blue Quartzite (Primary mineral: Quartz, SiO2 with magnesio-riebeckite or crocidolite inclusions)

Gabbro

Phaneritic Basic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)

Quartzite

Quartzite (primarily Silicon Dioxide, SiO2)

Gold Nugget

Native Gold (Au)

Red Quartzite

Quartzite (primarily SiO2)

Blue Quartzite

Quartzite (SiO2 with inclusions)

Sapphirine in Matrix

Sapphirine (Mg,Al)8(Al,Si)6O20

Black Obsidian

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

Quartz (specifically Milky/Yellow Quartz)

Silicon Dioxide (SiO2)

Quartzite Cobble

Quartzite (SiO2)

Quartz (specifically Milky or Rose Quartz variant)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (Primary mineral: SiO2)

Quartz Crystal (Amethyst)

Silicon Dioxide (SiO2)

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)

Banded Calcite (often commercially called Mexican Onyx)

Calcite (Calcium Carbonate, CaCO3)

Quartz (Float/Abraded)

Quartz (SiO₂)

Blue Apatite

Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)

Quartzite river stone

Quartzite (SiO2)

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Basalt with Limonite stains

Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)

Titanium Aura Quartz (Aura Quartz)

Titanium-coated Silicon Dioxide (SiO2)

Sea Glass (Frosted Quartz/Glass)

Amorphous Silicon Dioxide (SiO2)

Native Copper with Malachite and Chrysocolla

Native Copper (Cu) with Malachite [Cu2CO3(OH)2] and Chrysocolla [(Cu,Al)2H2Si2O5(OH)4·nH2O]

Nephrite Jade

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

Dyed Agate

Silicon Dioxide (SiO2) with artificial pigment

Diorite

Diorite (Intermediate intrusive igneous rock)

Banded Jasper

Silicon Dioxide (SiO2)

Dyed Magnesite (Howlite imitation)

Magnesium carbonate (MgCO3) with dye