Sedimentary Or Igneous Fragment

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz fragment (Pebble)

Silicon Dioxide (SiO2)

Yellow chalcedony or quartz fragment

Microcrystalline quartz, SiO₂ (tentative; possibly iron-stained chalcedony)

Banded quartz-rich metamorphic rock (likely quartzite or quartz-mica schist)

Quartzite/schist composed chiefly of SiO₂ quartz with mica, feldspar, and iron-oxide or copper-colored accessory minerals

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Polished garnet-bearing gneiss

Biotite-quartz-feldspar gneiss with almandine garnet (garnet: Fe₃Al₂(SiO₄)₃)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartz / Quartz Geode fragment

Silicon Dioxide (SiO2)

Small pale mineral fragment

Unidentified; possibly quartz, calcite, or feldspar

Small gray rock fragment, likely granite or diorite

Uncertain; probable coarse-grained silicate rock dominated by feldspar and quartz, possibly biotite/hornblende

Garnet in Host Rock

Garnet Group (A3B2(SiO4)3)

Quartz Crystal Fragment

Quartz (Silicon Dioxide, SiO2)

Small tumbled quartz-like pebble

Likely quartz (SiO₂), possibly iron-stained chalcedony or feldspar

Geode

Quartz nodule / Chalcedony-lined cavity

Granite fragment

Granite; chiefly quartz, alkali feldspar, and plagioclase, with minor mica or amphibole

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Weathered brown stone, possibly basalt or iron-rich sedimentary rock

Indeterminate from photograph; likely fine-grained mafic rock (basalt) or ferruginous sandstone

Quartz (Smoky or Clear variety with inclusions)

Silicon Dioxide (SiO2)

Small rounded pebble, likely quartz-rich river stone

Indeterminate; likely quartz/chert-bearing lithic clast

Weathered sandstone

Quartz-rich sandstone (lithified arenite)

Tourmaline-rich schist (likely black tourmaline)

Schist containing schorl, Fe-rich NaFe3Al6(BO3)3Si6O18(OH)4

Polished garnet-bearing metamorphic rock

Likely garnet mica schist or garnet-bearing gneiss; garnet is commonly almandine, Fe₃Al₂(SiO₄)₃

Garnet-bearing schist or gneiss

Garnet-mica schist/gneiss; chiefly quartz, feldspar, mica, and almandine–pyrope garnet

Quartz (Milky/Sugar variety)

Silicon Dioxide (SiO2)

Weathered quartz-rich metamorphic rock, likely gneiss or quartzite

Quartz (SiO₂)-bearing gneiss; exact identification requires a fresh surface and tests

Gneiss

Gneiss (Metamorphic Rock)

Coarse Sand or Fine Gravel

Detrital Sedimentary Fragments (mostly SiO2)

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Small translucent mineral fragment, possibly quartz

Quartz (SiO₂), tentative identification

Uncertain blue-white mineral fragment

Possibly calcite or quartz; identification is limited because the specimen is tiny and partly translucent

Quartz

Silicon Dioxide (SiO2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Banded metamorphic rock, likely schist or gneiss

Foliated quartz–feldspar–mica rock; exact mineral identification requires sampling

Quartz Cluster (Likely Ferruginous)

Silicon Dioxide (SiO2)

Quartz vein fragment

Milky quartz (SiO₂), possibly with weathered host rock

Unidentified greenish-gray rock fragment

Tentatively altered basalt or basaltic volcanic rock; mineral identification requires testing

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Healer's Gold (Pyrite and Magnetite in Schist)

Magnetite (Fe3O4) and Pyrite (FeS2) in Mica Schist

Oyster shell fragment

Ostreidae shell; primarily calcite (CaCO₃)

White quartz fragment

Quartz (silicon dioxide, SiO₂)