Antropogenic (Man Made)

Quartz

Silicon Dioxide (SiO₂)

Green cabochon gemstone, likely aventurine or dyed chalcedony

Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony

Obsidian

Obsidian (volcanic glass)

Chert / Flint

Chert (varieties include Flint)

Turquoise ring

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; the setting appears to be silver-colored metal

Possible tektite or volcanic glass specimen

Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing

Pearl (Biogenic Mineraloid)

Calcium carbonate (CaCO3) primarily as Aragonite

Possible basaltic volcanic rock or iron-rich meteorite

Likely basalt (plagioclase–pyroxene rock); meteorite status cannot be confirmed visually

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Coquina

Bioclastic Limestone

Chalcedony (likely agate)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Polished hematite (specimen identification uncertain)

Hematite, α-Fe₂O₃

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Diamond (Cut Gemstone)

Carbon (C)

Polished jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with possible iron-oxide and other mineral inclusions

Chert

Chert (Microcrystalline Quartz)

Pearl

Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin

Sandstone

Arenite (mostly SiO2)

Granite

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

Calligraphy Stone

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

Synthetic Convention Badge (Plastic/PVC)

Polyvinyl Chloride (PVC) / Polycarbonate

Sandstone

Arenite (with iron oxide cement)

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Gypsum (Satin Spar / Alabaster variety)

Calcium Sulfate Dihydrate (CaSO4·2H2O)

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)

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Diamond

Diamond (pure Carbon, C)

Exposed aggregate concrete (stone-chip surface)

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

Sandstone

Arenite (SiO2 primarily)

Chalk

Carbonate rock (mainly CaCO3)

Diamond

Carbon (C)

Weathered concrete or cementitious slab (not natural rock)

Artificial calcium-silicate cement composite; likely Portland cement concrete

Flint (gray chert)

Microcrystalline quartz (SiO₂), a variety of chert

Diamond (in Jewelry)

Carbon (C)

Quartzite

Metamorphic Quartz Rock (SiO2)

Quartzite

Metamorphic Quartzite (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Chalk

Micrite (primarily Calcium Carbonate or CaCO3)

Orange glassy slag (industrial by-product)

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