Sedimentary And Igneous (Mixed)

Bumblebee Jasper

Anhydrite with Sulfur, Hematite, and Orpiment (SiO2/CaSO4 mixture)

Garnet crystals

Garnet-group silicates, likely almandine (Fe₃Al₂Si₃O₁₂)

Graphite

Graphite (Native Carbon, C)

Iron-stained quartz-rich rock (possibly weathered quartz vein material)

Quartz-rich, iron-oxide-stained rock; exact lithology cannot be determined from the photograph

Mixed Tumbled Gemstones (Agate, Aventurine, Pyrite, etc.)

Multiple (principally Silicon Dioxide SiO2 and Iron Disulfide FeS2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Granite (weathered fragment)

Granite; chiefly quartz, alkali feldspar, plagioclase, and mica

Volcanic breccia or conglomeratic volcanic rock

Lithic volcanic breccia; possibly andesitic–basaltic matrix with feldspar-rich clasts

Weathered granite or granitic rock fragment

Granite; chiefly quartz, feldspar, and mica

Iron-stained conglomerate or breccia

Ferruginous clastic rock; likely quartz-rich sandstone with angular to rounded lithic clasts cemented by iron oxides

Mixed beach gravel and cobbles

Polylithic alluvial or littoral clasts, including quartz, quartzite, chert, limestone, sandstone, and flint

Granite (Pink/Potassium Feldspar Granite)

Felsic Plutonic Rock (Potassium Feldspar, Quartz, Mica, and Amphibole)

River Rock (Glacial Cobbles)

Fluvial Alluvium (Mixed lithology including Quartzite, Basalt, and Granite)

Weathered rounded cobble

Indeterminate lithology; likely weathered sandstone or volcanic rock

Tumbled jasper or chert pebble

Microcrystalline quartz (SiO₂), likely jasper/chert with iron-oxide staining

Crushed limestone gravel

Limestone; predominantly calcite (CaCO₃), possibly dolomitic limestone with dolomite (CaMg(CO₃)₂)

Mixed tumbled quartz specimens

Quartz, silicon dioxide (SiO₂), including rose quartz and milky/included varieties

Rounded gravel / river pebbles

Polymictic alluvial gravel, commonly quartz-, feldspar-, and lithic-rich clasts

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly mixed with chalcopyrite or other iron sulfides

Likely gray granite fragment

Granite, composed mainly of quartz, feldspar, and mica

Likely marble (calcite-rich metamorphic rock)

Calcite marble, composed mainly of calcite (CaCO₃); identification is provisional from the image

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica, with iron-oxide weathering

Petrified Wood and Mixed Rocks

Silicified Wood (SiO2)

Mixed rock and mineral specimens

Multiple unidentified silicate rocks and minerals; likely quartz-bearing material, feldspar, mica, and iron-oxide-bearing stones

Weathered polymictic gravel/conglomeratic rock

Polymictic conglomerate or poorly lithified alluvial gravel; chiefly quartz, feldspar, mica, and dark lithic fragments

Mixed rounded gravel and weathered rock fragments

Polymictic alluvial or glacial gravel; composition appears to include basaltic, quartz-rich, and feldspathic clasts

Pink Granite

Phaneritic Plutonic Felsic Rock (K-feldspar rich)

Dalmatian Jasper

Microcrystalline Quartz with Arfvedsonite/Tourmaline inclusions

Orange-brown rock fragment, likely iron-stained sandstone

Quartz-rich sandstone with iron-oxide staining (tentative visual identification)

Mixed rounded rock and mineral gravel

Predominantly weathered basalt, quartz-rich fragments, and iron-stained silicate rocks; exact species cannot be determined reliably from the image

Graphite

Graphite (Native Carbon, C)

Tumbled quartz-rich stone, possibly granite or rhyolite

Likely quartz (SiO₂) with feldspar and minor mica or other inclusions

Crushed granite aggregate

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, alkali feldspar, plagioclase, and minor mica/amphibole

Tumbled granite or granitic gneiss pebble

Granite/granitic gneiss, chiefly quartz, feldspar, and dark biotite or amphibole

Granite

Granite; primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende

Asphalt / Bituminous Aggregate

Bituminous mixture (Hydrocarbon-based sediment)

Mixed rock fragments, likely basalt and weathered granite

Basalt (mafic volcanic rock) and granitic fragments (quartz–feldspar–mica aggregate)

Mixed rounded river pebbles, likely basalt and granite

Basalt (fine-grained mafic rock) and granite/granitoid (quartz–feldspar rock)

Likely amazonite-bearing pegmatite

Amazonite (green microcline feldspar, KAlSi₃O₈) with quartz and mica or other pegmatite minerals

Biotite granite (likely weathered granite)

Granite; quartz + feldspar + biotite, with accessory dark minerals

Conglomerate (pebble conglomerate)

Clastic sedimentary rock composed of rounded gravel-sized clasts in a finer matrix

Mixed rock specimens; likely pink feldspar/quartz and a dark, mica-bearing rock

Tentative visual identification: pink K-feldspar–quartz-rich granite/pegmatite fragments and a dark amphibole- or biotite-rich metamorphic rock; exact identification is uncertain from the image