Mineral Or Sedimentary (If Chert)

Quartz or possibly Jasper/Chert. Looks like a tumbled or water-worn stone.

SiO2 (Silicon Dioxide)

Rounded pebble (likely quartz-rich sandstone or weathered chert)

Indeterminate from image; possibly quartz (SiO₂)-rich lithic material

Small brown pebble, possibly chert or jasper

Undetermined silica-rich pebble; possibly microcrystalline quartz (SiO₂)

Tumbled quartz-rich pebble, possibly smoky quartz or chert

Quartz (SiO₂), or microcrystalline quartz if chert

Weathered iron-rich river pebbles

Likely ferruginous chert or iron-stained siliceous/conglomeratic rock; exact identification is uncertain from the photograph

Tumbled chalcedony or quartz-rich stone

Microcrystalline quartz, SiO₂; possibly pale chert or chalcedony

Rounded brown pebble, likely weathered basalt or iron-rich chert

Indeterminate; possibly basalt (fine-grained mafic silicate rock) or ferruginous chert

Worn quartz-rich pebble

Likely microcrystalline quartz (SiO₂), possibly a weathered chert or milky quartz fragment

Chert Nodule in Limestone

Chert (Microcrystalline Quartz, SiO2) and Limestone (Calcium Carbonate, CaCO3)

Polished picture jasper heart pendant

Picture jasper (microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions)

Black Pebble (Basalt / Chert)

SiO2 (if Chert) or Mafic Igneous Rock (if Basalt)

Chert (Pink and Yellow Chert)

Microcrystalline Quartz (SiO2)

Chert on Volcanic Host Rock

Sedimentary Chert (SiO2) within Basalt or Andesite

Unidentified pale yellow-green mineral/rock fragment

Possibly sulfur-bearing mineral, serpentine, or weathered limestone; exact identification requires testing

Green Chert

Silicon Dioxide (SiO2)

Yellow Chert (Yellow Jasper)

Silicon dioxide (SiO2)

Flint/Chert Nodule in Limestone

Sedimentary rock containing microcrystalline quartz (SiO2) within a calcium carbonate (CaCO3) matrix

Small brown quartz-rich pebble, possibly chert or jasper

Microcrystalline quartz (SiO₂), tentative

Chert (likely chalcedony-rich flint)

Microcrystalline quartz, SiO₂ (quartz/chalcedony)

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Reddish weathered volcanic rock, probably andesite

Andesite (fine-grained plagioclase–pyroxene volcanic rock), possibly altered basalt

Coarse-grained gray metamorphic rock, likely gneiss

Biotite–quartz–feldspar gneiss (probable)

Banded Iron Formation

Banded Iron Formation (BIF)

Chert with Chalcedony/Quartz Vug

Cryptocrystalline Silica (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Chert nodules in Limestone

Microcrystalline Quartz (SiO2) in Calcium Carbonate (CaCO3) matrix

Chert

Chert (Microcrystalline Quartz, SiO2)

Chert (Jasper variety)

Chert (SiO2)

Chert (and Fossiliferous Chert)

Silicon Dioxide (SiO2)

Weathered chert or silicified limestone nodule

Microcrystalline quartz (SiO₂), possibly replacing limestone; exact identification requires testing

Chert (Jasper)

Sedimentary Cryptocrystalline Quartz (SiO2)

Weathered chert or siliceous limestone

Microcrystalline quartz (SiO₂), possibly with carbonate minerals

Blue Impression Jasper beads

Impression jasper (microcrystalline quartz/chalcedony), chiefly SiO₂, with iron-oxide and other mineral inclusions

Chert flake or weathered flint

Microcrystalline quartz (SiO₂), commonly termed chert or flint

Chert Nodules in Limestone / Fault Breccia

Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) matrix

Chert

Chert (SiO2)

Chert (Brecciated Chert)

Silicon Dioxide (SiO2)

Tumbled green calcite

Calcite (CaCO₃), likely pale green variety

Chert (with Calcite layering)

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3)

Chert

Microcrystalline Quartz (SiO2)

Chert

Chert (Microcrystalline Quartz, SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)