All rocks & minerals

Chert

Chert (Microcrystalline Quartz, SiO2)

Basalt with Olivine (Peridot)

Basalt containing (Mg,Fe)2SiO4

Micro-Meteorite (Micrometeoroid)

Extraterrestrial Spherule (Silicate or Iron-Nickel)

Specular Hematite

Hematite (Fe2O3)

Basalt

Extrusive mafic igneous rock

Basalt

Basalt

Anthracite Coal

Anthracite (Carbon C)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Serpentine

Antigorite, Lizardite, and Chrysotile (Mg3Si2O5(OH)4)

Basalt

Basalt (Aphanitic Mafic Igneous)

Quartzite

Metamorphic Quartz (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Sandstone

Arenite

Basalt

Basalt

Basalt (River Stone)

Basalt

Basalt

Basalt (Mafic volcanic rock)

Quartzite River Rock

Quartzite

Basalt

Extrusive mafic rock

Basalt (with Iron Staining)

Mafic Igneous Rock

Sandstone

Arenite (typically composed of SiO2)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Magnetite or Hematite-rich Ore

Magnetite (Fe3O4) or Hematite (Fe2O3)

Basalt (with possible fine-grained mineralization)

Basalt (Mafic Extrusive Igneous Rock)

Limestone with Fossil Inclusion

Sedimentary Calcium Carbonate (CaCO3)

Basalt

Basalt (Mafic volcanic rock)

Milky Quartz

Silicon Dioxide (SiO2)

Basalt with Olivine inclusion

Mafic Volcanic Basalt (Fe,Mg)2SiO4

Chert

Chert (Microcrystalline Quartz, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Belemnite Fossil

Belemnitida (Order within Cephalopoda)

Chert / Flint

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Turquoise

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

Vesicular Basalt

Extrusive mafic igneous rock

Basalt

Basalt (Igneous Volcanic)

Sandstone

Arenite (primary component SiO2)

Basalt

Basalt (Mafic volcanic rock)

Quartzite with inclusions

Quartzite (SiO2)

Quartzite

Quartzite (SiO2)