Amber (Burmite)
Fossilized tree resin (Succinite variant)
Organic mineraloid
Gneiss
Gneiss
metamorphic
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Scoria (Lava Rock)
Scoria (vesicular basaltic rock)
igneous
Petrified Wood (Calamites Fossil)
Calamites sp. (Silicified/Permineralized Plant Fossil)
sedimentary
Megalodon Shark Tooth (Partial Fossil)
Otodus megalodon (fossilized in Calcium Phosphate/Apatite)
Mineral/Fossil
Magnetite / Iron Ore
Magnetite (Fe3O4)
mineral
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
sedimentary
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
sedimentary
Sugilite
Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)
mineral
Amber
Succinite (fossilized tree resin)
mineraloid
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossilized Oyster Shell
Gryphaea or Crassostrea fossil (Calcium Carbonate, CaCO3)
sedimentary
Basalt (Vesicular/Scoria)
Vesicular Basalt
igneous
Sandstone Concretion
Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)
sedimentary
Anthracite Coal
Anthracite
metamorphic
Sandstone (with Iron Siderite Concretion)
Arenite with Ironstone Concretion (FeCO3)
sedimentary
Chalcedony Geode Fragment
Microcrystalline Quartz (SiO2)
mineral
Chert (Jasper/Flint variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Staurolite
Staurolite (Fe2+2Al9Si4O23(OH))
metamorphic
Chert (Nodular)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Sandstone (with ripple marks)
Arenite / Quartz Sandstone
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Limestone (specifically Travertine or Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Puddingstone
Conglomerate (Indurated)
sedimentary
Tektite (Indochinite)
Tektite (Silica-rich natural glass)
mineral
Basalt River Pebble
Mafic volcanic rock (Basalt)
igneous
Basalt River Stone
Basalt
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Epidote
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
metamorphic
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) in a Secondary Formation
sedimentary
Pyrite with Calcite
Iron Disulfide (FeS2) with Calcium Carbonate (CaCO3)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Galena
Lead(II) sulfide (PbS)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
mineral
Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
metamorphic