Man Made Glass (Not A Natural Rock Or Mineral)

Granite (with a dark inclusion or attached fragment)

Granite, mainly quartz, feldspar, and mica; the dark object cannot be identified confidently from the photo.

Sandstone

Clastic sedimentary rock (Quartz arenite)

Tumbled greenstone / serpentinite (probable)

Serpentinite, chiefly Mg-rich serpentine minerals (antigorite, lizardite, chrysotile), possibly mixed with chlorite, magnetite, or carbonate

Granite

Phaneritic Felsic Igneous Rock

Diamond (faceted)

Diamond (Pure Carbon, C)

Red-and-white jasper/chalcedony pebble

Microcrystalline quartz (SiO₂), likely hematite- or iron-oxide-bearing jasper with white chalcedony/quartz

Fossilized Bored Limestone

Limestone with Ichnofossils (Gastrochaenolites or Entobia)

Citrine

Silicon Dioxide (SiO2)

Polished white chalcedony or milky quartz pebble

Chalcedony, microcrystalline quartz (SiO₂), possibly with iron-oxide staining or a minor mineral inclusion

Sandstone

Sedimentary Clastic Rock

Sandstone

Arenite (primarily Quartz Arenite)

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Chalk

Micrite (primarily Calcium Carbonate, CaCO3)

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Pink Granite

Phaneritic Felsic Igneous Rock (composed of orthoclase, quartz, and plagioclase)

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Possible yellow agate or chalcedony bead

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

Sandstone

Arenite

Red bead-and-chain costume jewelry, likely glass or plastic

No geological identification; the red beads appear manufactured and cannot be identified as mineral from the image

Beaded mineral/crystal jewelry (likely turquoise and coral accents)

Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials

Sandstone

Arenite (primarily SiO2)

Sandstone

Clastic Sedimentary Rock

Diamond

Carbon (C)

Sandstone

Clastic sedimentary rock composed mainly of quartz and feldspar

Blue gemstone cross pendant

Likely faceted blue topaz (Al₂SiO₄(F,OH)₂); identification is uncertain from the image

Sandstone

Sedimentary Clastic Rock

Greenstone / serpentinite carving

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing

Sandstone

Arenite (composed primarily of SiO2)

Blue glassy cabochon, likely blue quartz or synthetic glass

Possibly dyed blue chalcedony/quartz (SiO₂); visual identification is inconclusive

Polished blue gemstone bead bracelet, likely aquamarine

Aquamarine, blue variety of beryl (Be₃Al₂Si₆O₁₈); identification from the image is uncertain

Chert

Silicon dioxide (SiO2)

Blue-and-white opalite sphere

Opalite (commercial synthetic or glass-based imitation; not true opal), typically silica glass or synthetic opalescent material

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3)

Sandstone

Arenite (SiO2 based)

Diamond

Carbon (C)

Diamond

Carbon (C)

Beach Pebble (Chalcedony / Chert)

Silicon Dioxide (SiO2)

Sandstone

Arenite (Clastic Sedimentary Rock)

Blue Chalcedony (likely dyed Agate)

Silicon Dioxide (SiO₂)

Obsidian

Volcanic Glass

Chert / River Pebble

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (SiO2 based typically)