Anthropogenic (Man Made Material Processed By Nature)

Rough Diamond

Diamond (Native Carbon, C)

Chert (Nodule)

Cryptocrystalline Quartz (SiO2)

Diamond

Carbon (C)

Calcite (or Alabaster, if truly carved)

Calcium Carbonate (CaCO3)

Diamond (Faceted)

Carbon (C)

Shale

Fissile mudstone (rich in clay minerals and quartz)

Quartzite

Metamorphic Quartz Sandstone

Quartzite

Metamorphic Quartzite (SiO2)

Diamond

C

Diamond

Diamond (pure carbon, C)

Diamond in Kimberlite

Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)

Engineer Quartz/Quartzite

SiO2 (Silicon Dioxide with binders)

Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)

Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement

Weathered quartz-rich cobble, possibly quartzite or feldspar-rich granite

Quartz–feldspar aggregate; identification is uncertain from the photograph

Polished tiger iron

Tiger iron; interlayered hematite, jasper, and crocidolite-quartz (often riebeckite)

Limestone (River Pebble)

Calcite (Calcium Carbonate) - CaCO3

Tumbled agate (probable moss or dendritic agate)

Microcrystalline quartz, SiO₂, with iron/manganese dendritic inclusions

Diamond (faceted)

Diamond (Pure Carbon, C)

Weathered quartz-rich rock, possibly sandstone or quartzite

Likely quartzite (mostly SiO₂), though a granular sandstone is also possible

Diamond (or Diamond Simulant)

Carbon (C) if diamond, various if simulant (e.g., Cubic Zirconia ZrO2)

Chert (Chalk-associated Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Vesicular volcanic rock, likely weathered pumice or scoria

Pumice/scoria; predominantly volcanic glass and feldspar, with possible iron oxides

Obsidian

Obsidian (Volcanic Glass)

Diamond

Carbon (C)

Sandstone

Arenite

Shale

Shale (clay-rich mudstone)

Chert (Flint Nodules)

Chert (Silicon Dioxide, SiO2)

Diamond (or Diamond Simulant like Cubic Zirconia)

Carbon (C) - if Diamond; Zirconium dioxide (ZrO2) - if Cubic Zirconia

Rhodonite

Rhodonite (MnSiO3)

Diamond

Diamond (pure Carbon, C)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Diamond

Carbon (C)

Diamond

Diamond (C)

Diamond

C (Carbon)

Diamond (or Cubic Zirconia imitation)

Carbon (C) - Native Element

Milky Quartz

Silicon Dioxide (SiO2)

Diamond (or Diamond Simulant)

Carbon (C) if diamond, various if simulant (e.g., Cubic Zirconia ZrO2)

Diamond (Cluster Ring)

Carbon (C)

Obsidian (Black)

Obsidian (High-silica volcanic glass)

Mica-rich schist

Muscovite–biotite schist, commonly quartz-bearing

Planet Earth

Gaia (Silicate Terrestrial Planet)

Quartz (Citrine or Smoky variety)

Silicon Dioxide (SiO2)