Anthropogenic (Man Made Industrial Byproduct)

Quartzite

Metamorphic Rock (Mainly SiO2)

Obsidian (Black)

Obsidian (High-silica volcanic glass)

Diabase (Greenstone)

Diabase (Dolerite)

Likely flint pebble (possibly a worked flint fragment)

Microcrystalline quartz (chalcedony), SiO₂; commonly called flint

Diamond (Pear Cut)

Carbon (C)

Sandstone

Arenite

Jade bangle

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

Sandstone (specifically Arkose or Quartz Arenite)

Arenite (primarily SiO2 with possible Feldspar)

Turquoise cabochon ring

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Small polished gemstone chips, likely mixed quartz varieties

Quartz (SiO₂), possibly including smoky quartz and other varieties; exact identification is uncertain from the image

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Red Sandstone

Arenite (with Iron Oxide / Hematite staining)

Iron-rich meteorite candidate

Unclassified iron meteorite or stony-iron meteorite; confirmation requires chemical and nickel testing

Limestone

Calcareous sedimentary rock (CaCO3)

Ferruginous Sandstone (Ironstone)

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

Weathered iron-rich rock, possibly jasper or ironstone

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

Talc

Talc (Mg₃Si₄O₁₀(OH)₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz geode

Quartz (SiO₂), likely a chalcedony-lined geode with druzy quartz

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Blue glassy mineral fragment, possibly kyanite or blue quartz

Indeterminate from image; candidates include kyanite (Al₂SiO₅) or blue quartz (SiO₂)

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Small dark pebble, possibly basalt or slag

Likely fine-grained mafic rock; exact identification requires examination

Banded Calcite or Travertine

Calcium Carbonate (CaCO3)

Opal ring (likely precious opal)

Hydrated amorphous silica, SiO₂·nH₂O; the pictured stone may be natural opal or a lab-created/imitation opal

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Tiny amber-colored crystal or mineral fragment

Indeterminate from image; possibly quartz, citrine, topaz, or iron-stained feldspar

Small gray rock fragment

Indeterminate; possibly quartz-rich granite, chert, or concrete-like silicate material

Quartz-lined vesicle in basalt (amygdaloidal basalt)

Amygdaloidal basalt with drusy quartz; predominantly plagioclase, pyroxene, and iron oxides

Green Fluorite

Calcium Fluoride (CaF2)

Small faceted diamond-like gemstones

Likely diamond (crystalline carbon, C), but visual identification is uncertain

Water-worn pebble, likely fine-grained volcanic rock

Unidentified mafic volcanic rock; possibly andesite or basalt

Fossil brachiopod in limestone

Brachiopoda; commonly a spiriferid or strophomenid brachiopod preserved in calcite-rich limestone

Polished ironstone concretion with quartz/iron-oxide vein

Goethite–hematite-rich ironstone concretion, likely veined by quartz or chalcedony

Milky quartz fragment

Quartz, silicon dioxide (SiO₂)

Granite

Granite (felsic intrusive igneous rock)

Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (primarily SiO2)

Uncertain polymict breccia or altered volcanic rock

Likely hydrothermally altered volcanic breccia; exact mineral identification requires testing

Fossilized bone fragment

Petrified vertebrate bone; mineralized hydroxyapatite replaced or infilled by silica/carbonates

Iron-rich concretion or slag-like mineral fragment

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

Possible ironstone concretion or weathered mineral nodule

Iron-oxide-rich concretion, likely goethite/limonite; identification uncertain from the photo

Iron-stained quartz vein rock

Quartz-rich rock with iron-oxide/hydroxide coatings (hematite/goethite); exact host rock undetermined