Mineraloid (Man Made)

Likely rough green-blue glassy mineral fragment

Unidentified; the image is insufficient to distinguish a natural mineral from industrial slag or glass

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone composed of Hematite and Shell remains)

Tumbled carnelian

Carnelian, a red-orange variety of chalcedony (microcrystalline quartz, SiO₂)

Polished hematite

Hematite, iron(III) oxide (α-Fe₂O₃)

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Quartzite

Metamorphic Quartz Arenite (SiO2)

Quartzite

Metamorphic Quartz Arenite

Chert (likely flint)

Microcrystalline quartz (SiO₂), variety chert; flint is a dark chert variety

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Gypsum (Satin Spar / Alabaster variety)

Calcium Sulfate Dihydrate (CaSO4·2H2O)

Polished carnelian agate

Microcrystalline quartz (SiO₂), chalcedony variety; orange-red color commonly from iron oxides

Sandstone

Arenite (with iron oxide cement)

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Quartzite

Metamorphic Quartz Arenite

Likely chert (flint)

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

Limestone Pebble

Sedimentary Calcium Carbonate (CaCO3)

Quartzite

Metamorphic Quartzite (SiO2)

Greenstone, likely serpentinite

Serpentinite; predominantly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, chlorite, and talc

Flint (chert)

Microcrystalline quartz, SiO₂

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Diamond

Diamond (pure Carbon, C)

Quartzite

Metamorphic Quartz Arenite (SiO2)

Sandstone

Arenite (SiO2 primarily)

Chalk

Carbonate rock (mainly CaCO3)

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Kyanite

Aluminium Silicate, Al2SiO5

Black obsidian

Volcanic glass; predominantly rhyolitic silica glass (approximately 70–80% SiO₂)

Flint (gray chert)

Microcrystalline quartz (SiO₂), a variety of chert

Tumbled yellow-brown chalcedony (likely agate)

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

Diamond (in Jewelry)

Carbon (C)

Weathered iron-rich sandstone or ironstone cobble

Ferruginous sandstone/ironstone, chiefly quartz (SiO₂) cemented or stained by iron oxides and hydroxides

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

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)

Small yellow-orange mineral fragment, likely amber or iron-stained quartz

Possibly amber (fossilized resin; organic mineraloid) or quartz (SiO₂)

Tumbled carnelian (reddish-orange chalcedony)

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

Quartzite

Metamorphic Quartz Rock (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)