Industrial Byproduct (Anthropogenic Material)

Sandstone (Ferruginous)

Arenite with Iron Oxides

Pyrite

Iron Sulfide (FeS2)

Diamond

Carbon (C)

Polished brecciated jasper or iron-rich agate

Microcrystalline quartz (SiO₂), with hematite/goethite and possible iron oxides

Diamond

C (Carbon)

Mica-rich schist (likely biotite schist)

Biotite schist; quartz- and feldspar-bearing, with abundant mica

Serpentine

Serpentine group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al)2O5(OH)4)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Basalt (Phaneritic or Diabase)

Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)

Quartzite Pebble

Quartzite (SiO2)

Quartzite

Quartzite (mostly SiO2)

Basalt

Basalt (Ma-Fe Silicate)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Basalt

Basalt (Aphanitic Mafic Volcanic Rock)

Granodiorite

Granodiorite (Na,Ca)(Al,Si)4O8

Quartzite

Quartzite (SiO2)

Basalt

Basalt

Basalt (Vesicular/Scoria)

Vesicular Basalt

Quartzite

Quartzite (SiO2)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Diamond

Native Carbon (C)

Diamond (or Cubic Zirconia)

Cubic Carbon (C) or Zirconium Dioxide (ZrO2)

Small dark pebble, possibly basalt

Unidentified fine-grained mafic rock; basalt is a tentative visual match

Asphalt Concrete

Bituminous Concrete

Diamond (in a gold ring)

Diamond (pure carbon, C)

Diamond

Carbon (C)

Small pale stone (unidentified)

Undetermined; image detail is insufficient for reliable identification

Diamond

Carbon (C)

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz/chalcedony with iron- and manganese-bearing inclusions; SiO₂

Polished kambaba jasper (orbicular rhyolite)

Silicified orbicular rhyolite, commonly sold as kambaba jasper; orbicular patterns may include quartz, feldspar, and amphibole/chlorite minerals

Diamond

C

Blue-gray stone pebble (possibly slag or a weathered rock)

Unidentified fine-grained rock; composition cannot be determined from the image

Vesicular iron-rich slag or weathered metallic ore

Indeterminate; likely Fe-oxide-bearing slag (magnetite/hematite) rather than a specific natural mineral

Polished botryoidal jasper/chalcedony (likely ocean jasper)

Microcrystalline quartz, SiO₂, with iron-oxide and other mineral inclusions

Weathered quartz-rich rock or fossil fragment

Indeterminate; likely quartz-bearing sandstone or siliceous fossil material

Diamond

Carbon (C)

Dalmatian jasper

Quartz-bearing alkali feldspar syenite/porphyritic igneous rock, commonly marketed as Dalmatian jasper

Possible polished or tumbled stone

Unidentified; the image does not show enough detail to determine its composition

Dalmatian jasper (polished stone beads)

Commercial “Dalmatian jasper”; typically a feldspar-rich rock with dark aegirine or arfvedsonite inclusions, not true jasper

Black-and-white bicolored pebble

Likely basalt with a pale felsic or carbonate coating/inclusion; exact identification requires testing

Quartz Nodule

Silicon Dioxide (SiO2)