Man Made Silicate (Anthropogenic Glass)

Druzy quartz-bearing rock

Quartz, SiO₂, as a druse coating or quartz-rich vein material

Cobalt Blue Sea Glass

Amorphous Silica Glass (SiO2 + CoO)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Green-speckled igneous rock, likely epidote-bearing basalt or serpentinite

Tentatively epidote-bearing basalt (compositionally uncertain from the image)

Weathered quartz-rich pebble

Likely quartz-bearing rock; precise identification is limited by the blurry image

Pumice

Vesicular volcanic glass (primarily Alumino-silicates)

Likely weathered gneiss or granite fragment

Quartz–feldspar–mica aggregate; probably granitoid gneiss, identification uncertain from the photograph

Tumbled Agate Pebble

Silicon Dioxide (SiO2)

Obsidian (Black)

Obsidian (High-silica volcanic glass)

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Diamond (or Diamond Simulant)

Carbon (C) or Cubic Zirconia (ZrO2)

Blue Goldstone

Aventurine Glass (Silicon Dioxide with metal inclusions)

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Olivine-rich peridotite / olivine crystal fragment

Olivine, typically (Mg,Fe)₂SiO₄; possibly peridotite if the specimen is rock rather than a single crystal

Feldspar (specifically Orthoclase)

Potassium aluminum silicate (KAlSi3O8)

Tumbled pink feldspar pebble

Potassium feldspar, commonly microcline or orthoclase (KAlSi₃O₈)

Beryl (likely Aquamarine)

Beryllium aluminum silicate (Be3Al2Si6O18)

Aquamarine (Beryl) Beads

Beryllium aluminum silicate (Be3Al2Si6O18)

Yellow Beryl (Heliodor)

Beryllium aluminum silicate (Be3Al2Si6O18)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Potassium Feldspar (Orthoclase)

KAlSi3O8 (Potassium Aluminum Silicate)

Faceted Glass (Costume Jewelry)

Amorphous Silicon Dioxide with colorants (Glass)

Rough Sapphire (Corundum)

Corundum (Al2O3)

Pumice or vesicular volcanic tuff

Pumice: highly vesicular volcanic glass, chiefly rhyolitic to dacitic; possible tuff: lithified ash and pumice fragments

Chert Nodule

Microcrystalline Quartz (SiO2)

Chert (specifically Flint)

Chert (SiO2)

Rounded gray pebble, likely quartzite

Quartzite (predominantly crystalline quartz, SiO₂); identification is tentative from the image

Chert (Flint)

Silicon Dioxide (SiO2)

Green glassy slag or manufactured glass bead

Noncrystalline silicate glass; likely industrial glass/slag, not a true mineral

Quartz-rich rock fragment, possibly granite or quartzite

Indeterminate quartz-bearing silicate rock; likely quartz (SiO₂) with feldspar and/or mica

Tumbled feldspar-rich pebble (probable)

Likely potassium feldspar, orthoclase or microcline (KAlSi₃O₈), though the photograph is not diagnostic

Small brown pebble (likely iron-stained quartz or chert)

Undetermined silicate pebble; possible quartz (SiO₂) or chert (microcrystalline SiO₂)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Quartz Pebble

Silicon Dioxide (SiO2)

Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Chert

Silicon dioxide (SiO2)

Artificial Rock Face (Faux Rock)

Glass Fiber Reinforced Concrete (GFRC)

Quartz

Silicon Dioxide (SiO2)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Feldspar (Orthoclase)

Potassium Alveolar Silicate (KAlSi3O8)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)