Anthropogenic (Man Made Material)

Diamond

Diamond (C)

Chert Pebble

Chert (Silicon Dioxide, SiO2)

Chert / Flint

Silicon Dioxide (SiO2)

Silicon Carbide (Carborundum)

Moissanite (SiC)

Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variously known as Flint)

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Kaolinite (Chalky Clay)

Kaolinite (Al2Si2O5(OH)4)

Chert (Flint/Jasper)

Silicon dioxide (SiO2) - Microcrystalline quartz

Yellow chalcedony (likely citrine or iron-stained quartz)

Microcrystalline quartz, SiO₂; yellow coloration likely from iron oxides or included quartz varieties

Red Sandstone

Arenite (Ferruginous Sandstone)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Iron Meteorite

Siderite (Iron-Nickel Meteorite)

Chert (often called Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Polished rhyolite (likely porphyritic rhyolite)

Rhyolite, composed chiefly of quartz and alkali feldspar with minor plagioclase, biotite, and iron oxides

Tumbled carnelian/chalcedony

Cryptocrystalline quartz, SiO₂ (iron-bearing chalcedony)

Tumbled serpentine (likely)

Serpentine-group minerals, commonly lizardite or antigorite; approximate composition Mg₃Si₂O₅(OH)₄

Weathered volcanic rock, likely andesite or basalt

Fine-grained mafic to intermediate volcanic rock; probable andesite–basalt, compositionally dominated by plagioclase with pyroxene and possibly alteration minerals

Quartz geode / iron-stained quartz vein rock

Quartz (SiO₂), likely with iron oxides and minor feldspar or host-rock minerals

Polished jasper pebble

Jasper, microcrystalline quartz (SiO₂), commonly with iron-oxide impurities

Leopard Skin Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (River Stone)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (SiO2)

Red Sandstone

Arenite (SiO2 with Fe2O3)

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Chalcedony (likely agate/chert variety)

Microcrystalline quartz, SiO₂

Chert (Flint)

Microcrystalline Quartz (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Amethyst-bearing quartz (likely polished or naturally fractured)

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related defects

Small purple quartz crystal, likely amethyst

Amethyst: violet variety of quartz, silicon dioxide (SiO₂)

Fossil scallop/bivalve shell

Fossilized pectinid bivalve; likely family Pectinidae (exact genus/species cannot be determined from the image)

Malachite / Copper Ore

Cu2CO3(OH)2

Chrysocolla

Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O

Diamond

Carbon (C)

Slate

Metamorphic Pelitic Rock

Chert / Flint Pebble

Silicon Dioxide (SiO2)

Slate

Foliated Metamorphic Rock

Diamond

C (Carbon)

Chert / Flint

SiO2 (Silicon Dioxide)