Organic Material (Likely A Fruit Or Berry)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Pink tourmaline crystal (probable)

Elbaite tourmaline, Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Tumbled dark stone, likely basalt or chert

Basalt (fine-grained mafic rock), possibly weathered chert; exact identification requires testing

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Iron-stained quartz-rich rock, possibly quartzite or hydrothermal quartz

Quartz (SiO₂), likely with iron oxides; exact host rock uncertain from the photograph

Chert (variations include Chalcedony and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Greenstone / altered basalt fragment

Likely chlorite–epidote–actinolite altered basalt; exact identification requires testing

Banded Chert

Microcrystalline Quartz (SiO2)

River Rocks (Polished River Pebbles)

Stream-rounded clastic sediments

Fossilized Horn Coral

Rugosa (Tetracoralla)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Chert (often called Flint for dark variants)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Carved lavender chalcedony (likely agate) animal figurine

Microcrystalline quartz, SiO₂; probable chalcedony or pale lavender agate

Rose quartz (likely)

Quartz, silicon dioxide (SiO₂), pink variety

Limestone

Calcareous sedimentary rock (CaCO3)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Quartz-rich pegmatite with mica and dark inclusions

Pegmatite; chiefly quartz (SiO₂), with feldspar and biotite/tourmaline inclusions

Chert (Yellow Jasper/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Milky quartz (likely quartzite or massive quartz)

Quartz, silicon dioxide (SiO₂)

Polished porphyritic basalt (likely)

Basalt, a fine-grained mafic volcanic rock; visible inclusions may be olivine, feldspar, or vesicle infillings

Sandstone (likely Graywacke or Siltstone variety)

Clastic Sedimentary Rock (SiO2 with assorted mineral fragments)

Rounded gray stone, likely quartz-rich granitic rock

Probable granite or granitic gneiss; mainly quartz, feldspar, and mica

Likely polished garnet fragment

Garnet group, possibly almandine (Fe₃Al₂Si₃O₁₂)

Fossilized ammonite (likely weathered ammonite cross-section)

Ammonoidea; commonly Jurassic–Cretaceous ammonite fossils replaced by calcite or aragonite

Biotite-bearing gneiss or schist

Quartz–feldspar–biotite metamorphic rock

Sandstone (Micaceous/Feldspathic variant)

Arenite (specifically subarkose or lithic arenite)

Tumbled quartz (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Chert (with Quartz veins)

Microcrystalline quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Sandstone (likely Fossiliferous)

Arenite / Sedimentum arenaceum

Red jasper (likely hematite-rich jasper)

Microcrystalline quartz (SiO₂) with iron oxides, chiefly hematite (Fe₂O₃)

Tumbled ruby-bearing corundum

Corundum (Al₂O₃), likely ruby variety

Tumbled yellow jasper or serpentine

Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄

Polished dark-green stone, possibly serpentine or nephrite jade

Serpentine-group minerals, commonly antigorite/lizardite; possible nephrite (actinolite–tremolite amphibole)

Chert / River Jasper

Microcrystalline Quartz (SiO2)

Chert (Quartz Pebble)

Silicon Dioxide (SiO2)

Sandstone (with Iron Staining)

Arenite (Silicon Dioxide, SiO2, often with iron oxides like Limonite)

Chert (specifically Flint or Common Chert)

Microcrystalline Quartz (SiO2)

Red jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored mainly by iron oxides

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Rhyolite or jasper-bearing volcanic rock

Rhyolite, likely altered and silicified; red coloration may come from hematite