This Is Not A Rock Or Mineral

Druzy Quartz on Chert/Chalcedony

Silicon Dioxide (SiO2)

Gneiss (Metamorphic Pebble)

Gneissic Metamorphic Rock

Dalmatian Jasper

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Sandstone (Weathered Cobble)

Clastic sedimentary rock (primarily SiO2)

Copper-bearing Quartz Vein in Host Rock

Quartz with Malachite/Chrysocolla staining

Weathered granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly gneiss if the dark minerals are banded

Quartz Druzy (Geode Fragment)

Silicon Dioxide (SiO2)

Tumbled yellow jasper (probable)

Jasper, an opaque microcrystalline variety of quartz; chiefly SiO₂ with iron-oxide inclusions

Greenstone pebble (likely altered basalt or serpentine)

Greenschist-facies mafic rock; commonly chlorite–actinolite–epidote ± serpentine

River Rock with Quartz Vein

Basalt or Andesite with Quartz Veining

Granite or Granitic Gneiss River Rock

Granite

Milky Quartz with Country Rock contact

Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock

Granite

Intrusive Igneous Rock

Sandstone

Arenite (primarily SiO2)

Veined Quartzite / Vein-filled Sedimentary Rock

Siliciclastic rock with iron oxide-filled fractures

Granite

Intrusive Igneous Rock

Quartz-rich rock, likely milky quartz vein material

Quartz (SiO₂), possibly with iron-oxide staining and minor associated minerals

Vein Quartz in Basalt or Mafic Rock

Silicon Dioxide (Quartz veins in volcanic host rock)

Tumbled brecciated jasper (likely ocean or mahogany jasper)

Jasper—microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions

Agate Geode

Silicon Dioxide (SiO2) - Chalcedony variety

Granite-like rock

Felsic intrusive igneous rock, probably granitic or granodioritic

Pebble

Clast (specifically a granule or small pebble)

Sandstone

Sandstone (clastic sedimentary rock)

Greenstone (likely metamorphosed mafic rock)

Probable chlorite–actinolite–epidote-rich metabasalt; exact identification requires testing

Green serpentine (likely serpentine-rich stone)

Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; composition approximately Mg₃Si₂O₅(OH)₄

Red Sandstone

Arenite (Iron-rich)

Granite boulder

Granite, chiefly quartz–feldspar–mica plutonic rock

Weathered granitic boulder

Granite, typically composed of quartz, feldspar, and mica

Small rounded pebble (rock type indeterminate)

Unidentified lithic pebble; specific composition cannot be determined from the image

Weathered granite

Granite, a quartz–feldspar–mica intrusive igneous rock

Sandstone (Wonderstone)

Clastic Sedimentary Rock (primarily SiO2)

Greenish rough stone, possibly serpentine or soapstone

Indeterminate from the image; possible serpentinite (serpentine-group minerals) or talc-rich soapstone

Milky quartz vein rock

Quartz (SiO₂), likely in a quartz-rich host rock with minor iron-stained minerals

Shale

Argillite / Shale

Basalt with Granite Inclusions (Xenoliths)

Mafic igneous rock (Basalt) with Sialic minerals

Smoky Quartz and Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone and Conglomerate pebbles

Sedimentary clastic rock

Shale

Shale (clastic sedimentary rock)

Banded Gneiss Pebble

Gneiss (Metamorphic Rock)

Pegmatitic gneiss with a quartz–feldspar vein

Quartz–feldspar-rich gneiss, locally cut by a granitic pegmatite vein

Chalcedony Geode

Silicon Dioxide (SiO2)