Man Made Material (Simulated Mineral)

Blue-green fluorite (likely tumbled/polished)

Fluorite, calcium fluoride (CaF₂)

Mixed river pebbles and quartz-rich specimens

Polymictic fluvial gravel; likely quartz, quartzite, chert, and weathered feldspathic rocks

Greenschist (Chlorite Schist)

Greenschist (containing Chlorite, Actinolite, and Epidote)

Weathered iron-rich rock, possibly limonite-bearing sandstone or laterite

Limonite/goethite-rich ferruginous rock; exact identification requires testing

Quartz Pebble

Silicon Dioxide (SiO2)

Tumbled amethyst

Quartz, crystalline silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone with Iron Staining

Arenite (SiO2 with Fe2O3)

Petrified Wood

Silicified wood (SiO2)

Petrified Wood

Silicified wood (SiO2 - Silicon Dioxide)

Granite

Granite (Felsic Plutonic Rock)

Diorite

Diorite (intermediate intrusive igneous rock)

Granite Pebble

Intrusive Igneous Rock (Felsic to Intermediate)

Tumbled orange chalcedony or jasper

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Polished tree agate (likely)

Chalcedony (microcrystalline SiO₂) with green dendritic/inclusion minerals

Tektite (Indochinite)

Natural glass (High-silica impact glass)

Chalcedony

Silicon dioxide (SiO2)

Diamond

Diamond (C)

Muscovite Mica (in Quartz matrix)

Potassium aluminum silicate hydroxide fluoride (KAl2(AlSi3O10)(F,OH)2)

Malachite in Matrix

Copper Carbonate Hydroxide (Cu2CO3(OH)2)

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Sandstone

Sandstone (various mineral compositions)

Milky Quartz

Silicon dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Brecciated jasper/chalcedony

Silica-rich breccia composed mainly of microcrystalline quartz (SiO₂), with iron-oxide and possibly epidote or chlorite inclusions

Likely dark green-gray metamorphic pebble

Indeterminate; possibly chlorite schist, serpentinite, or amphibolite

Polished/tumbled jasper

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

Sandstone (Yellow/Siltstone variant)

Arenite (SiO2 primarily)

Quartz

Silicon Dioxide (SiO2)

Diamond (Set in Jewelry)

Carbon (C)

Siltstone

Siltstone

Biotite-bearing granite or granitic gneiss

Quartz–feldspar granite with biotite mica; possibly weakly foliated gneiss

Tumbled green aventurine (probable)

Quartz aggregate, SiO₂, commonly containing fuchsite mica inclusions

Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock

Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Porphyritic basalt (likely amygdaloidal basalt)

Basalt containing larger plagioclase crystals and pale vesicle-fill minerals, commonly calcite, zeolite, or quartz

Bronzite

(Mg,Fe)SiO3

Lepidolite (in Quartz Matrix)

Lepidolite [K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2]

Chrysocolla on Quartz/Rhyolite matrix

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Flint

Microcrystalline Quartz (SiO2)

Flint

SiO2 (Cryptocrystalline Quartz)