Sedimentary Rock (Possibly Conglomerate Or Breccia With A Quartz Vein)

Jasper

Chalcedony (SiO2)

Weathered river cobble, possibly sandstone or volcanic tuff

Indeterminate lithology; likely fine-grained sandstone/siltstone, with possible iron-oxide veining

Sandstone (with Quartz Vein/Inclusion)

Arenite (primarily SiO2)

River Pebble (Granite / Sandstone Cobble)

Stream-rounded Rock Pebble

Quartz-veined Basalt or Limestone Pebble

Quartz vein in host rock (Silicate mineral in carbonate or volcanic matrix)

River Pebbles (Mixed Lithology)

Conglomerate clasts (Silica-rich and Metamorphic assemblages)

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Polygenetic Conglomerate (Puddingstone)

Conglomerate (SiO2 matrix with mixed clasts)

Weathered quartz-rich rock, likely quartzite

Quartzite (mostly microcrystalline quartz, SiO₂), possibly weathered quartz vein material

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Jasper and Chert Conglomerate

Ferruginous Microcrystalline Quartz (SiO2)

Vuggy quartz-rich breccia

Silicified volcanic or hydrothermal breccia; mainly microcrystalline quartz (SiO₂), with possible calcite and iron-oxide minerals

Gravel and Pebbles

Unconsolidated rock fragments (clastic sediment)

Tumbled quartz-rich pebble, likely milky quartz with iron-oxide staining

Quartz (SiO₂), possibly with hematite/goethite inclusions or surface coating

Conglomerate (River Rock)

Clastic sedimentary rock (primarily SiO2)

Brecciated Jasper

Silicon Dioxide (SiO2) with hematite and other mineral impurities

Gravel and River Pebbles

Unconsolidated rock fragments / Detrital sediment

Hagstone (Adder Stone)

Chert or Sedimentary pebble with natural perforation

Likely weathered iron-rich breccia or jasper

Silicified iron-oxide breccia; exact identification requires testing

Tumbled quartz-rich pebble, likely milky quartz

Quartz (silicon dioxide, SiO₂), possibly iron-stained milky quartz

Dark gray fine-grained rock fragment

Likely basalt (possibly andesite); exact identification is limited by the photograph

Tumbled dark limestone or basalt with a pale mineral vein

Likely micritic limestone (calcite, CaCO₃), possibly basalt with a calcite/quartz vein

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Druzy Quartz on Matrix

Silicon Dioxide (SiO2)

Likely quartz-rich rock fragment

Quartz (silicon dioxide, SiO₂), possibly milky quartz or a quartz-bearing stone

Red jasper in a gray host rock (likely jasperized volcanic rock)

Microcrystalline quartz (SiO₂), iron-oxide–colored jasper, in a fine-grained volcanic or sedimentary matrix

Quartz Vein in River Siltstone

Crystalline Quartz (SiO2) in Siliclastic Matrix

Chert Breccia

Brecciated Chert (Microcrystalline Silica, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Vein in Schist

Quartz (SiO2) in Pelitic Schist

Iron-rich breccia (likely hematite–goethite breccia)

Hematite (Fe₂O₃) and goethite (FeO(OH)) in a silicified or iron-cemented breccia

River Pebbles (Chert and Quartzite)

Sedimentary Clastic Rock (Silica-rich)

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Pyrite in Quartz Matrix

Iron Sulfide (FeS2) embedded in Silicon Dioxide (SiO2)

Weathered quartz-rich rock, possibly iron-stained quartzite

Quartzite (predominantly SiO₂), tentatively; may instead be quartz vein material or chert

Polished brecciated jasper

Silicified breccia, chiefly microcrystalline quartz (SiO₂) with iron-oxide staining

Likely tumbled quartz-rich pebble

Quartz (SiO₂), possibly a weathered quartzite or chalcedony pebble

Small rounded pale stone

Indeterminate; likely quartz-rich pebble, possibly quartz or light-colored feldspar

Mixed River Pebbles and Rock Collection

Polymictic lithic conglomerate, sandstone, and quartz pebbles

Sandstone with Quartz Vein

Quartzose Sandstone with Hydrothermal Quartz

Puddingstone

Polymictic Conglomerate