Man Made Material, Not A Natural Rock Or Mineral Specimen

Sandstone (with Limonite staining)

Arenite (primarily SiO2 with FeO(OH)·nH2O)

Moss Agate

Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)

Sandstone (Quartz-rich)

Arenite (composed primarily of SiO2)

Chert (specifically Zebra Chert/Flint)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 primarily)

Lazulite

Lazulite (Mg,Fe2+)Al2(PO4)2(OH)2

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2)

Wonderstone (Sandstone)

Liesegang Banded Sandstone (SiO2 dominated)

Quartz (Microcrystalline variety)

Silicon Dioxide (SiO2)

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Agate (Crazy Lace or Eye Agate)

Silicon Dioxide (SiO2)

Eclogite

Eclogite (Omphacite + Pyrope)

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Pink Tumbled Agate (Dyed)

Silicon Dioxide (SiO2) with artificial dyes

Quartz Pebble

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide)

Sandstone (Ferruginous)

Arenite (Fe2O3 staining)

Dalmation Stone (Dalmation Jasper)

Peralkaline rock (primarily Feldspar and Quartz with Arfvedsonite spots)

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

Turquoise

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

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily Quartz with Fe2O3 staining)

Green Aventurine

Quartz (SiO2) with Fuchsite inclusions

River Quartz Pitting/Cobble

Silicon Dioxide (SiO2)

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Sandstone Concretion with Quartz Center

Sedimentary Clastic Rock (SiO2 matrix with Quartz core)

Ocean Jasper

Silicon dioxide with impurities (SiO2 + impurities)

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Satin Spar (Gypsum)

Hydrous Calcium Sulfate (CaSO4·2H2O)

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Quartz (Milky/Crystal Variety)

Silicon Dioxide (SiO2)

Carnelian Agate Nodule

Silicon Dioxide (SiO2) - Carnelian Chalcedony

Satin Spar (Selenite)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Picture Jasper

Silicified sedimentary or volcanic rock (primarily SiO2)

Sandstone (lithic wacke/arenite)

Clastic sedimentary rock (primarily SiO2)

Turquoise

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

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Banded Agate (specifically Lake Superior Agate)

Silicon dioxide (SiO2) - Cryptocrystalline Chalcedony