Sedimentary Or Igneous Fragment

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Likely weathered sandstone fragment

Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement

Fine-grained sedimentary rock (likely sandstone)

Quartz-rich sandstone; exact identification is uncertain from the image

Unidentified brown rock fragment

Not identifiable from the image; possibly iron-stained sandstone or another common weathered rock

Weathered limestone fragment

Limestone, chiefly calcite (CaCO₃)

Unidentified small brown rock

Undetermined; image does not show enough detail for reliable identification

Reddish-brown rock fragment, possibly iron-stained sandstone

Unidentified iron-oxide-stained rock; sandstone is a tentative visual identification

Weathered gray stone fragment

Undetermined; possibly limestone or sandstone

Chalcedony Geode Fragment

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Moss-covered Rock Fragment

Weathered Rock Fragment with Epilithic Growth

Tumbled fossiliferous limestone

Micritic limestone, likely bioclastic/fossiliferous carbonate rock (predominantly CaCO₃)

Likely banded sandstone fragment

Quartz-rich sandstone (composition cannot be confirmed from the image)

Fossilized shell or bone fragment

Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone

Milky quartz

Quartz (SiO₂)

Pyrite

Iron Sulfide (FeS2)

Weathered granite or granitic gneiss fragments

Granite; chiefly quartz, feldspar, and biotite/hornblende

Light-colored volcanic pumice (probable)

Pumice, vesicular volcanic glass; typically silica-rich rhyolitic to dacitic composition

Weathered quartz-rich rock fragment

Likely granitic or pegmatitic fragment; chiefly quartz (SiO₂) with feldspar and iron-oxide staining

Granite (small weathered fragment)

Granite, composed chiefly of quartz, feldspar, and mica

Quartz-bearing rock fragment

Undetermined quartz-rich rock; visible white material is likely quartz (SiO₂), with dark fine-grained host rock

Likely porphyritic volcanic rock

Indeterminate; possibly porphyritic andesite or basalt

Small rock fragment (unidentified)

Undetermined; the image does not show enough detail for reliable identification

Weathered granite (probable)

Granite; chiefly quartz, feldspar, and minor mica

Likely rough granite or granitic rock fragment

Granite (quartz–feldspar–mica assemblage; exact identification is uncertain from the image)

Granite (likely)

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica

Light-colored volcanic rock fragment, likely pumice or tuff

Pumice (vesicular volcanic glass) or volcanic tuff; not identifiable more precisely from the image

Likely quartz-bearing rock fragment

Undetermined; possibly quartz-rich granitic or volcanic rock

Fossiliferous Limestone

Biogenic Sedimentary Rock

Fossiliferous Limestone

Biogenic Sedimentary Rock (Calcium Carbonate)

Chert with Fossils

Microcrystalline quartz (SiO2)

Limestone with Fossil Fragments

Bioclastic Limestone (CaCO3)

Possible blue topaz or glassy blue mineral fragment

Indeterminate from image; possibly topaz (Al₂SiO₄(F,OH)₂)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Tumbled dark pebble, likely hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄); identification is uncertain from the image alone

Weathered quartz-rich rock fragment

Likely quartz-bearing feldspathic fragment; exact identification requires testing

Likely quartz-rich rock fragment

Indeterminate; probably microcrystalline quartz (SiO₂) with minor feldspar or weathering minerals

Small brown mineral fragment, possibly quartz/chert

Uncertain; likely microcrystalline quartz (SiO₂) or a weathered silicate rock

Milky Quartz

Silicon Dioxide (SiO2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Possible fossilized shell or coral fragment

Indeterminate biogenic carbonate, likely calcite (CaCO₃)