Anthropogenic (Man Made Product Subject To Geological Processes)

Porphyritic Basalt (or Andesite) Pebble

Porphyritic Mafic Volcanic Rock

Polished red jasper pendant

Jasper, an opaque, microcrystalline variety of quartz (SiO₂), colored red by iron oxides

Red jasper pebble (likely)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored by iron oxides

Weathered quartz-rich sandstone, possibly iron-stained quartzite

Quartz sandstone (quartz arenite), SiO₂-rich; exact identification requires hardness and texture tests

Chert / Flint

Cryptocrystalline Quartz (SiO2)

Likely iron-rich slag or weathered ironstone

Hematite–goethite-rich material (Fe₂O₃/FeO(OH)); possibly industrial iron slag

Quartzite

Quartzite (SiO2)

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Likely red-and-green jasper (rough pebble)

Microcrystalline quartz (SiO₂), colored by iron oxides; exact identification requires testing

Blue Chalcedony and Picture Jasper Beads

Blue Chalcedony (SiO2), Picture Jasper (SiO2)

Tumbled red-brown jasper

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

Goldstone

Aventurine glass

Petrified wood

Silicified wood, commonly quartz or chalcedony (SiO₂) replacing ancient wood

Mixed rock and mineral specimens

Predominantly quartz-rich rocks, with a possible malachite-bearing specimen; exact identification is uncertain from the image

Polished brecciated jasper (likely Apache tear–type iron-rich jasper)

Jasper, microcrystalline quartz (SiO₂), colored by hematite/goethite and other iron oxides

Polished yellow jasper

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

Polished red jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Weathered, iron-stained quartz-rich rock (possibly quartzite)

Likely quartzite, composed mainly of quartz (SiO₂); identification is provisional from the image

Iron-stained quartz-bearing rock

Quartz (SiO₂), likely with limonite/goethite iron oxides and possibly feldspar

Polished yellow jasper cabochon

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay inclusions

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Rounded river pebble, likely basalt or dark volcanic rock

Fine-grained mafic igneous rock; possibly basalt (identification uncertain from photograph)

Red coral earrings

Corallium rubrum or related precious coral (calcareous coral skeleton; primarily aragonite, CaCO₃)

Likely serpentine (serpentinite) pebbles

Serpentine-group minerals, chiefly antigorite, lizardite, and/or chrysotile; commonly Mg₃Si₂O₅(OH)₄, sometimes containing magnetite, chromite, and minor carbonate minerals

Possible iron meteorite fragment

Iron–nickel meteorite, likely kamacite–taenite alloy

Quartzite

Quartzite (SiO2)

Quartz (beads)

SiO2 (Silicon Dioxide)

Quartzite

Metamorphosed Quartz Sandstone

Coal (Anthracite or Bituminous)

Carbon (C) with varying hydrocarbon and mineral impurities

Rhodonite

Rhodonite (Mn2+SiO3)

Opalite (Man-made Glass)

Synthetic Opalised Glass

Quartzite

Metamorphic quartz-rich rock

Blue topaz cross pendant

Topaz, Al₂SiO₄(F,OH)₂; likely faceted blue topaz

Tumbled brown jasper (likely iron-rich chalcedony)

Jasper, opaque microcrystalline quartz (SiO₂), commonly colored by iron oxides

Tumbled jasper (likely picture jasper)

Jasper, an opaque microcrystalline variety of quartz (SiO₂); exact variety uncertain from the photo

Ruby in Zoisite

Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende

Slate

Slate; fine-grained metamorphosed shale, commonly mica- and chlorite-rich

Milky quartz with iron-oxide staining

Quartz, silicon dioxide (SiO₂), cryptocrystalline-to-coarse crystalline aggregate

Red vesicular volcanic rock, likely scoria

Scoria (mafic pyroclastic rock), typically basaltic and composed mainly of plagioclase, pyroxene, and iron-rich glass

Polished striped jasper pebble

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay inclusions

Quartzite

Quartzite (primarily Silicon Dioxide, SiO2)

Pitted Limestone with Honeycomb Weathering

Karst-weathered fossiliferous limestone (CaCO3)