Anthropogenic (Man Made)

Jade bangle

Likely nephrite jade (actinolite–tremolite amphibole); possibly jadeite

Sandstone (specifically Arkose or Quartz Arenite)

Arenite (primarily SiO2 with possible Feldspar)

Limestone

Calcareous sedimentary rock (CaCO3)

Red Sandstone

Arenite (with Iron Oxide / Hematite staining)

Ferruginous Sandstone (Ironstone)

Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)

Fossilized sea urchin

Echinoid test, likely a regular sea urchin; calcite (CaCO₃)

Fossilized echinoid (sea urchin), likely a sand dollar fragment or small regular urchin

Echinodermata; commonly Clypeasteroida or Echinoida, preserved mainly as calcite (CaCO₃)

Weathered iron-rich rock, possibly jasper or ironstone

Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Quartzite Pebble

Quartzite (SiO2)

Banded Calcite or Travertine

Calcium Carbonate (CaCO3)

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Granite

Granite (felsic intrusive igneous rock)

Iron-rich concretion or slag-like mineral fragment

Likely limonite/goethite (FeO(OH)·nH₂O), possibly magnetite-bearing material

Garnet Beads

Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Granite Cobble/Pebble

Granite

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Granite

Granite (a plutonic rock)

Bog Iron / Limonite Concretion

Goethite/Limonite mixture (FeO(OH)·nH2O)

Crushed Limestone

Calcium Carbonate (CaCO3)

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

Granodiorite

Granodiorite

BROWN GRANITE (likely 'Tan Brown' or similar)

Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)

Granite (weathered pebble)

Granite (plutonic igneous rock)

Possible tektite or volcanic glass specimen

Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing

Possible basaltic volcanic rock or iron-rich meteorite

Likely basalt (plagioclase–pyroxene rock); meteorite status cannot be confirmed visually

Nephrite Jade

Nephrite

Quartz

Silicon Dioxide (SiO₂)

Faience and Carnelian in Egyptian Revival Jewelry

Faience (quartz frit) and Carnelian (chalcedony, SiO2)

Obsidian

Obsidian (volcanic glass)

Chert / Flint

Chert (varieties include Flint)

Turquoise ring

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; the setting appears to be silver-colored metal

Green cabochon gemstone, likely aventurine or dyed chalcedony

Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony

Pearl (Biogenic Mineraloid)

Calcium carbonate (CaCO3) primarily as Aragonite

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Coquina

Bioclastic Limestone

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Chert

Chert (Microcrystalline Quartz)

Diamond (Cut Gemstone)

Carbon (C)

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Pearl

Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin