Man Made Material, Not A Natural Rock Or Mineral Specimen

Gabbro Pebble (Polished Beach/River Stone)

Gabbro

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Moonstone

Orthoclase Feldspar ((K,Na)AlSi3O8) with Albite inclusions

Sandstone (Water-worn Pebble)

Clastic Sedimentary Rock (primarily SiO2)

Banded gneiss pebble

Gneiss, typically quartz–feldspar–mica assemblage

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Likely weathered iron-rich stone

Uncertain; possibly limonite/goethite-bearing rock

Diamond

Carbon (C)

Vesicular volcanic rock, possibly weathered basalt or scoria

Basaltic scoria/vesicular basalt; predominantly plagioclase, pyroxene, and iron-titanium oxides

Coarse-grained Granite

Granitoid (Felsic Plutonic Rock)

Gold-bearing Quartz (Auriferous Quartz)

Quartz (SiO2) with native Gold (Au) inclusions

Smoky Quartz (Vein Quartz)

Quartz (Silicon Dioxide, SiO2)

Mixed Mineral Collection (with Titanium Aura Quartz)

Silicon Dioxide (SiO2) with metallic coatings and various silicates

Diorite (River Cobble)

Intermediate plutonic igneous rock

Dalmatian Stone

Peralkaline igneous rock containing quartz, feldspar, and arfvedsonite

Banded metamorphic rock, likely mica schist or gneiss

Quartz–feldspar–mica schist/gneiss; exact identification requires a fresh surface and mineral tests

Petrified Wood

Silicified Wood (SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Wishing Stone with Quartz Vein

Quartz-veined sedimentary pebble

Tumbled carnelian (probable)

Cryptocrystalline silica, mainly chalcedony (SiO₂), colored orange-red by iron oxides

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

N/A - Image does not contain a rock or mineral

Anthropogenic textile material

Polished orbicular jasper (likely ocean jasper)

Jasper, microcrystalline quartz (SiO₂), colored by iron oxides and other inclusions

Quartz with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate [Ca2(Al,Fe)3(SiO4)3(OH)]

Green-and-gold apatite-bearing rock, possibly epidote skarn

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F), with probable epidote and quartz; exact identification requires testing

Granitic Quartz with Feldspar

Granite (composed primarily of SiO2 and KAlSi3O8)

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (SiO2 primary composition)

Sandstone (lithic/arkosic)

Clastic sedimentary rock (primarily SiO2)

Chert (Flint)

Microcrystalline quartz (SiO2)

Cubic Zirconia (CZ)

Cubic Zirconium Dioxide (ZrO2)

Quartzite Pebble

Quartzite (SiO2)

Turquoise in Matrix

Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O

Jasper (Iron-rich Chalcedony)

Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)

Tumbled ruby or ruby-bearing corundum

Corundum (Al₂O₃), red variety colored mainly by chromium

Weathered quartz-rich rock fragment

Likely quartz-bearing sandstone or granitic rock; exact identification is uncertain from the image

Turquenite (Dyed Howlite)

Dyed Ca2B5SiO9(OH)5 (Calcium Borosilicate Hydroxide)

Polished basalt with a quartz vein

Basalt, cut by milky quartz (SiO₂)

Clear Quartz

Silicon Dioxide (SiO2)

Green Fluorite in Host Rock

Fluorite (Calcium Fluoride, CaF2)

Tumbled epidote or epidote-rich stone

Epidote, Ca₂(Al,Fe)₃(SiO₄)₃(OH); possibly a green jasper or prehnite-epidote aggregate

Conglomerate

Clast-supported polymict conglomerate