Sedimentary (Base), Then Artificial

Slag

Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)

Tumbled coral limestone

Biogenic calcarenite/coral limestone, predominantly calcium carbonate (CaCO₃; calcite/aragonite)

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Tumbled quartz-rich pebble

Likely quartz-bearing chert or jasper; primarily microcrystalline SiO₂

Dyed pink agate slice

Agate (microcrystalline quartz, SiO₂), commonly chalcedony with artificial dye

Dyed Agate (Tumbled)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Likely black beach pebble

Undetermined; possibly basalt, chert, or dark slate

Dyed Quartz Pendant

Silicon Dioxide (SiO2) with artificial dye

Drill Core Sample

Cylindrical Rock Core (Specific mineralogy varies by extraction site)

Tumbled chalcedony or quartz pebble

Microcrystalline quartz, SiO₂ (likely chalcedony); exact identification is uncertain from the image

Carnelian (a variety of Chalcedony)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Agate (Dyed High-Grade Polished Slice)

Silicon dioxide (SiO2), Chalcedony crystal variety

Red sandstone pebble

Quartz-rich sandstone, commonly ferruginous sandstone (SiO₂-dominated)

Fossil Shark Tooth

Otodus sp. or Carcharocles sp. (likely fossilized Chondrichthyes)

Dalmatian Stone

Peralkaline Feldsphathic Igneous Rock

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Fossilized Shark Tooth

Eocene Lamniformes (Mackerel Shark clade)

Sandstone / Chert Gravel

SiO2 (Silicon Dioxide based clastic sedimentary rock)

Shale (or Mudstone/Siltstone)

Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)

Mixed sandstone and iron-rich sedimentary rock fragments

Quartz arenite/subarkose, with ferruginous cement and possible iron-oxide staining

Polished black stone, likely black jasper or basalt

Most likely microcrystalline quartz (black jasper/chert), SiO₂; basalt is a plausible alternative

Metal Alloy (Jewelry)

Not a naturally occurring rock or mineral; likely a metal alloy for jewelry. Possible compositions include sterling silver (92.5% silver, 7.5% copper), or other silver/gold alloys.

Pebble / Gravel

Clastic Sedimentary Specimen (likely Limestone or Quartzite base)

Green Chalcedony (Batu Akik)

Silicon Dioxide (SiO2)

Sandstone pebble

Sandstone (mainly Quartz, SiO2)

River Pebble (likely Quartzite or Siltstone)

Sedimentary Clast (SiO2 based)

Chalcedony with Druzy Quartz

Silicon Dioxide (SiO2)

Unidentified Rock

Unknown

Iron-stained weathered rock

Unknown

Sandstone

Arenite (SiO2 based sedimentary rock)

Fossilized Shark Tooth (Otodus obliquus)

Otodus obliquus (Mineralized Apatite / Bio-apatite)

Brecciated jasper (likely)

Silica-rich jasper/chert breccia, composed mainly of microcrystalline quartz (SiO₂)

Fossilized Crab Carapace (Concretion)

Decapoda (fossil), typically preserved in calcite or siderite concretion

Common Gravel / Pebble

Lithified rock fragment / Detrital sediment

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 based)

Painted Sandstone Cobble

Clastic Sedimentary Rock (Sandstone base)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Sandstone (Ferruginous)

Arenite with Iron oxide staining (SiO2 with Fe2O3)

Sandstone (River Rock)

Arenite (SiO2 based sedimentary rock)

Amethyst or Smoky Quartz Geode Slice

Crystalline Silicon Dioxide (SiO2) with iron impurities

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Sandstone (Pebble)

Sandstone (SiO2 dominated clastic sedimentary rock)