Man Made Composite

Tumbled yellow-brown chalcedony (likely agate)

Microcrystalline quartz, SiO₂; chalcedony, possibly iron-stained agate

Diamond (in Jewelry)

Carbon (C)

Blue-stone and diamond ring

Blue stone is possibly blue sapphire (corundum, Al₂O₃); surrounding stones appear to be diamonds (carbon, C).

Diamond

Carbon (C)

Rhodonite

Rhodonite, (Mn,Fe,Mg,Ca)SiO₃

Likely green bottle glass, not a geological specimen

Manufactured soda-lime silicate glass

Synthetic Zinc/Polycarbonate Composite (Bey-specimen)

Zinc Alloy (Zamak 3) with Polycarbonate (C15H16O2)n Overlay

Small dark mineral or rock fragment (not identifiable from the image)

Undetermined; the specimen is too small and lacks visible diagnostic features for a reliable identification.

Quartzite

Metamorphic Quartz Rock (SiO2)

Quartzite

Metamorphic Quartzite (SiO2)

Tumbled carnelian (reddish-orange chalcedony)

Chalcedony, microcrystalline quartz (SiO₂), colored by iron oxides

Quartzite

Metamorphic Quartz Rock (SiO2)

Sandstone Pebble

Arenite (primarily SiO2)

Sandstone (with potential mineral inclusions)

Clastic sedimentary rock (primarily Quartz, SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Quartzite

Metamorphic Quartz Rock (SiO2)

Yellow chalcedony (possibly iron-stained agate)

Microcrystalline quartz, SiO₂

Orange glassy slag (industrial by-product)

Iron-rich silicate glass; composition varies, commonly Fe–Ca–Al silicate

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Chalk

Micrite (primarily Calcium Carbonate or CaCO3)

Sandstone (Quartzose)

Sandstone (SiO2 dominated)

Pearl

Organic gemstone (Calcium carbonate - CaCO3)

Chert (variations include Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Coal (Bituminous Coal)

Caustobiolith / Sedimentary Rock

Sandstone

Arenite (SiO2 composition dominant)

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly milky quartz or quartzite

Diamond

Native Carbon (C)

Quartzite

Metamorphic Quartzite (SiO2)

Diamond

Carbon (C)

Diamond

Carbon (C)

Diamond

Carbon (C)

Multicolor quartz bead bracelet

Quartz (silicon dioxide, SiO₂); bead colors may be from different varieties or treated quartz

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Clastic Sedimentary Rock

Quartzite

Metamorphic Quartzite (SiO2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Red jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored chiefly by iron oxides

Sandstone

Arenite (typically composed of SiO2)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

Quartzite

Metamorphic Quartzite (SiO2)