Sedimentary

Tumbled brown stone, possibly jasper or weathered chert

Uncertain; likely microcrystalline quartz (SiO₂), potentially iron-stained jasper/chert

Weathered sandstone

Quartz-rich sandstone, locally iron-oxide stained (SiO₂-dominant)

Polished black stone, likely hematite or black jasper

Hematite (Fe₂O₃) or opaque chalcedony/jasper (SiO₂); image-only identification is uncertain

Chert / Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Geode in Sedimentary Host Rock

Silicon Dioxide (SiO2) in Carbonate Matrix

Jasper

Silicon dioxide (SiO2)

Quartz

Silicon dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Clear Quartz

SiO2 (Silicon Dioxide)

Pink Quartz

Silicon Dioxide (Quartz), SiO2

Mica

Mica group (often Muscovite or Biotite)

Polished Stone Pendant (Identity Unclear)

Unknown (Possibly Jasper/Agate/Quartz mixture)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Clear Quartz

Silicon Dioxide (SiO2)

Worn River Pebble with Fossil Indentation

Sedimentary Rock with Fossil Infill

Clear quartz crystal pendant

Quartz (silicon dioxide, SiO₂)

Weathered sandstone pebble

Quartz-rich sandstone; predominantly SiO₂ grains cemented by silica, calcite, or iron oxides

Rounded iron-rich river pebble, likely sandstone or ironstone

Indeterminate ferruginous sandstone/ironstone; exact identification requires closer examination

Likely milky quartz

Quartz (silicon dioxide, SiO₂)

Likely bituminous coal

Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed from the image

Banded sandstone

Quartz-rich sandstone (quartz arenite or feldspathic sandstone; exact type cannot be determined from the image)

Sandstone or Siltstone

Arenite or Siltstone

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Banded Iron Formation

Banded Iron Formation (BIF)

Glauconitic Sandstone

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

Rounded fossil fragment, possibly fossiliferous limestone

Unidentified carbonate fossil or fossil-bearing limestone; exact fossil cannot be determined from the photograph

Polished hematite

Hematite (Fe₂O₃), likely a tumbled specimen

Pyrite Cubes in Matrix

Iron Disulfide (FeS2) in Host Matrix

Quartz Geode Fragment

Crystalline Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Satin Spar Selenite

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Polished red jasper (likely hematite-bearing jasper)

Jasper, microcrystalline quartz (SiO₂), colored chiefly by iron oxides such as hematite/goethite

Jasper Pebble

Microcrystalline Quartz (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Satin Spar (Selenite)

Gypsum (CaSO4·2H2O)

Polished black limestone or chert pebble

Cryptocrystalline silica (chert) or calcitic limestone; exact identification is uncertain from the photograph

Sandstone (with ripple marks)

Arenite / Quartz Sandstone

Weathered sedimentary rock, likely sandstone

Quartz-rich sandstone (tentative identification)

Red Jasper

Microcrystalline Quartz (SiO2 with Iron Oxide impurities)

Jasper (Mookaite / Brecciated Jasper)

Microcrystalline Quartz (SiO2 with iron oxide inclusions)

Quartz pebble

Silicon dioxide (SiO2)