Man Made Material (Anthro Lithic Product)

Likely graphite-rich schist or graphite-bearing metamorphic rock

Graphite (C) in a mica/quartz-rich matrix; exact rock name requires testing

Ruby in Matrix

Corundum (Al2O3)

Likely chert (flint)

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

Sandstone (lithic/arkosic)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Sedimentary Rock (Quartz arenite / Lithic sandstone)

Weathered mafic rock, likely basalt or gabbro

Basalt–gabbroic rock; chiefly plagioclase feldspar and pyroxene, with possible olivine and magnetite

Weathered, iron-stained quartz-rich pebble (uncertain identification)

Microcrystalline quartz, SiO₂, with iron-oxide/hydroxide staining and dark matrix inclusions

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Tumbled amethyst

Quartz, crystalline silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Iron-rich concretion or weathered ironstone pebble

Goethite/limonite-bearing ironstone; commonly an iron-oxide concretion (FeO(OH)·nH₂O, variable)

Banded sandstone pebble

Quartz-rich sandstone, likely with a contrasting siltstone or fine-grained sandstone band

Red-orange sunstone (likely aventurine feldspar) bead bracelet

Feldspar, commonly oligoclase or labradorite with copper inclusions; composition varies by source

Polished greenstone (likely serpentine or altered basalt)

Serpentinite, mainly serpentine-group minerals (Mg₃Si₂O₅(OH)₄); exact identification requires testing

Quartz vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Lithic Matrix

Slate

Metamorphic Pelitic Rock

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Chert or Jasper

Microcrystalline Quartz (SiO2)

Coquina

Bioclastic Limestone

Blue chalcedony cabochon (probable)

Chalcedony, a cryptocrystalline variety of quartz; silicon dioxide, SiO₂

Engraved purple stone cabochon, possibly amethyst

Unconfirmed; if amethyst, quartz (SiO₂)

Chert (Sedimentary Rock)

Silicon Dioxide (SiO2)

Limestone

Limestone (Calcium Carbonate - CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

Polished stromatolite (likely fossilized microbial mat)

Fossil stromatolite; chiefly microcrystalline quartz (SiO₂), commonly replacing carbonate

Weathered sandstone pebble

Quartz-rich sandstone, commonly arkose or lithic sandstone

Chert (likely flint)

Microcrystalline quartz, SiO₂

Chert (specifically Flint or Novaculite variant)

Chert (Microcrystalline Quartz, SiO2)

Rounded quartz-rich pebble

Lithic pebble; likely quartz/quartzite with iron-oxide staining

Chert (specifically Yellow/Common Opal or Jasper mixture)

Silicon Dioxide (SiO2)

Weathered foliated metamorphic rock, likely schist or phyllite

Micaceous quartz–feldspar schist/phyllite; exact identification requires petrographic or chemical testing

Serpentinite pebble

Serpentinite, composed chiefly of serpentine-group minerals (lizardite, chrysotile, antigorite), with possible magnetite and chlorite

Banded sandstone

Quartz-rich clastic sandstone, likely ferruginous or arkosic

Porphyritic polymictic breccia (likely volcanic breccia)

Volcanic breccia; probable polymictic andesite–dacite breccia with quartz/feldspar clasts

Weathered basalt or volcanic scoria fragment

Basaltic volcanic rock; chiefly plagioclase, pyroxene, and iron-rich oxides

Sandstone (lithic/quartz variant)

Clastic sedimentary rock (SiO2 predominant)

Chert (Flint)

Silicon Dioxide (SiO2)

Limpets Shell / Fossil Specimen

Patellogastropoda (Class)

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

Weathered sandstone cobble

Clastic sandstone, likely quartz-rich arenite or arkose

Chert (often found as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)