Sedimentary (Secondary Mineral Formation)

Quartz Geode (Cracked)

Crystalline Silicon Dioxide (SiO2)

Seam Agate

Agate (Banded variety of Chalcedony, SiO2)

Turquoise

Hydrate phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Blue Chalcedony

Cryptocrystalline Silicon Dioxide (SiO2)

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)

Glauconite (Greensand)

Glauconite ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Chert Pebble (Jasper/Flint variant)

Microcrystalline Quartz (SiO2)

Tree Agate

Dendritic Chalcedony (SiO2)

Carnelian Agate

Silicon Dioxide (SiO2) with iron impurities

Agate (Turtle Carving)

Agate (Cryptocrystalline variety of Silica, SiO2)

Moss Agate

SiO2 (Silicon Dioxide) with dendritic inclusions

Shale (possibly Carbonaceous or Oil Shale)

Argillaceous Sedimentary Rock

Red Sandstone

Arenite (Ferruginous Sandstone)

Vesicular basalt (possible scoria)

Basaltic volcanic rock; chiefly plagioclase, pyroxene, and iron-rich minerals, with vesicles formed by trapped gas

Tumbled hematite

Hematite (iron(III) oxide, Fe₂O₃)

Sandstone

Arenite (primarily Quartz Arenite)

Possible ironstone concretion or weathered mineral nodule

Iron-oxide-rich concretion, likely goethite/limonite; identification uncertain from the photo

Native Copper

Native Copper (Cu)

Rounded river pebble (lithology unclear)

Indeterminate natural rock; no specific mineral or rock type can be identified from the image

Goethite (Iron Ore)

Goethite (FeO(OH))

Quartz

Silicon dioxide (SiO2)

Turquoise

Hydrated copper and aluminum phosphate (CuAl6(PO4)4(OH)8·4H2O)

Turquoise

Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O

Jasper / Agate with Petrified Wood Inclusion

SiO2

Small red-brown mineral or rock fragment

Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide

Chert (Jasper)

Silicon Dioxide (SiO2)

Sandstone fragments

Quartz-rich sandstone (likely), composed mainly of quartz grains cemented by silica, calcite, or iron oxides

Banded Iron Formation (BIF)

Banded Iron Formation

Dyed turquoise-colored howlite or magnesite (likely imitation turquoise)

Howlite: Ca₂B₅SiO₉(OH)₅; magnesite: MgCO₃

Blue Quartz (Blue Chalcedony/Dumortierite Quartz)

Silicon Dioxide (SiO2) with inclusions (typically Dumortierite Al7(BO3)(SiO4)3O3)

Honey Calcite Geode Segment

Calcite (Calcium Carbonate, CaCO3)

Chalcedony

Silicon dioxide (SiO2) - Microcrystalline quartz

Limonite (with Goethite/Ironstone)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Agate

Silicon Dioxide (SiO2)

Azurite Geode

Azurite (Cu3(CO3)2(OH)2)

Brecciated rock (possibly fault breccia)

Polymictic breccia; exact lithology cannot be determined from the photograph

Rounded river pebble

Unidentified lithic pebble; exact rock type cannot be determined from the image

Small rounded pebble

Unidentified lithic clast; likely fine-grained sandstone, mudstone, or basalt

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Weathered iron-rich rock (likely ironstone or altered basalt)

Probable limonite/goethite-bearing basalt or ironstone; exact identification requires testing

Likely biotite-rich schist

Mica schist, likely containing biotite and quartz; exact identification requires examination