Rock (Likely Sedimentary)

Quartz (likely a form of massive or vein quartz)

Quartz (SiO₂)

Fossiliferous Limestone

Sedimentary rock containing Indeterminate Fossil remains (likely Crinoid stem or Bryozoan fragment)

Pink-and-green quartz-rich rock, likely rose quartz with epidote/serpentine

Quartz (SiO₂), variably colored by iron, with possible epidote, chlorite, or serpentine inclusions

Gold in Quartz Matrix

Native Gold (Au) with Quartz (SiO2) and Slate/Shale

Quartz (likely Jasper or Chert variety)

Quartz (SiO₂)

Peridotite (Dunite)

Peridotite (mostly Olivine: (Mg,Fe)2SiO4)

Porphyritic Andesite

Andesite (Intermediate Volcanic Rock)

Dark mafic rock, likely basalt

Basalt (fine-grained assemblage chiefly plagioclase and pyroxene, commonly with olivine and iron oxides)

Dark igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and possibly olivine

Likely weathered basalt or basaltic rock

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine

Weathered quartz-rich cobble (probable quartzite or silicified rock)

Quartzite, predominantly SiO₂; exact identification is uncertain from the photograph

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Weathered granite or granitic gneiss slab

Granitic rock, chiefly quartz, feldspar, and mica; exact identification is uncertain from the photograph

Quartz

Silicon Dioxide (SiO2)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Crystalline Quartz (SiO2)

Quartz (Bull Quartz)

Silicon Dioxide (SiO2)

Fossilized Shell Impression / Siltstone Fossil

Bivalvia / Brachiopoda mold in Siltstone

Granite

Intrusive Igneous Rock (Felsic)

Basalt Porphyry

Porphyritic Basalt

Weathered volcanic rock, likely basalt

Basalt; commonly composed of plagioclase, pyroxene, and iron-rich oxides

Dark mafic rock, likely basalt

Basalt; primarily plagioclase feldspar and pyroxene, commonly with olivine and iron oxides

Weathered gray rock, likely basaltic or andesitic fragment

Fine-grained mafic to intermediate volcanic rock; exact identification requires fresh surface and testing

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂) with iron-oxide staining and minor feldspar/mica

Quartzite

Metamorphic Quartz (SiO2)

Unidentified weathered rock fragment

Likely granitic or feldspathic rock; exact identification requires clearer imaging and testing

Quartz geode / iron-stained quartz vein rock

Quartz (SiO₂), likely with iron oxides and minor feldspar or host-rock minerals

Brecciated jasper (likely red-and-cream jasper)

Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining

Banded Chert

Silicon Dioxide (SiO2)

Basalt Pebble

Basalt

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Pebble (likely Quartzite or Chert)

Clastic Sediment, potentially composed of SiO₂ (Quartz)

Andesite

Intermediate Volcanic Rock (Andesite)

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2) crystal conglomerate

Druzy Quartz Geode (likely Smokey Quartz variety)

Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.

Pearls

Pearl: biomineralized aragonite (CaCO₃) and conchiolin

Weathered granite fragment

Granite; chiefly quartz (SiO₂), feldspar, and mica

Dark granite or granitic gneiss

Granite; quartz + feldspar + biotite/hornblende, possibly weakly gneissic

Quartz Pebble

Silicon Dioxide (SiO2)

Vesicular volcanic rock, likely pumice or scoria

Pumice/scoria; predominantly volcanic glass with plagioclase, pyroxene, and/or olivine

Feldspar (specifically Orthoclase or Plagioclase)

Potassium Aluminum Silicate (KAlSi3O8) or Sodium/Calcium Aluminum Silicate

Banded Iron Formation (BIF) with Quartz

Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)