This Is Not A Rock Or Mineral

Granite Pebble

Intrusive Igneous Rock

Sandstone Pebble

Sandstone (Silicon dioxide-rich clastic sedimentary rock)

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Quartz Crystal on Matrix

Silicon Dioxide (SiO2)

Small weathered mineral/rock fragment

Unidentified; likely quartz-rich material, possibly quartzite or feldspar-bearing rock

Weathered granite or granitic gneiss pebble

Granite; primarily quartz, potassium feldspar, plagioclase, and mica

Greenstone (likely chlorite-rich metamorphic rock)

Chlorite-bearing greenschist; exact identification requires testing

Sandstone (River Cobble)

Clastic sedimentary rock (primarily SiO2)

Sandstone with Desert Varnish

Arenite (SiO2 predominantly) with Ferromanganese coating

Granite

Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)

Basalt

Basalt

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Sedimentary Rock Fragments

Clastic Sedimentary Rock

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

Lapis Lazuli

(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2 (Complex silicate rock)

Basalt with Quartz/Calcite Veins

Aphanitic Mafic Igneous Rock (Hydrothermal Veined)

Granite

Felsic intrusive igneous rock

Yellow-brown stone or mineral fragment

Unidentified; the image does not show enough detail for a reliable identification

Basalt (Vesicular or Porphyritic River Pebble)

Mafic Volcanic Rock (Aphanitic to Porphyritic Basalt)

Granite

Granite; primarily quartz, feldspar, and mica

Small cylindrical mineral/stone fragment

Undetermined; the image is insufficient for reliable mineral identification

Red jasper

Jasper, an opaque microcrystalline quartz variety (SiO₂), colored mainly by iron oxides

Granite

Intrusive Igneous Rock

Likely rough garnet

Garnet group, possibly almandine (Fe₃Al₂(SiO₄)₃); identification is uncertain from the image

Quartz Vein in Amphibolite / Gneiss

Quartz (SiO2) in Mafic Metamorphic Host Rock

Quartz Geode

Silicon Dioxide (SiO2) within a sedimentary or volcanic shell

Quartz Geode

Silicon Dioxide (SiO2)

Asphalt aggregate pavement

Bituminous asphalt concrete containing crushed stone aggregate

Quartz Geode

Silicon Dioxide (SiO2) in a sedimentary or volcanic host

Lapis Lazuli

(Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2 (Complex silicate rock)

Herkimer Diamond

Quartz (Silica - SiO2)

Unknown Tumbled Stone

Unknown (Too Blurry)

Quartz geode

Crystalline quartz (SiO₂), lining a geode cavity

Granite

Granite; chiefly quartz, feldspar, and mica

Weathered granite fragment

Granite, primarily quartz, feldspar, and mica

Gabbro or Diorite with Quartz/Epidote Vein

Intrusive Igneous Rock (Plutonic)

Unakite

Epidotized Granite

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Possible green tumbled stone

Unidentified green mineral or rock; the image is too blurred for reliable identification

Granite

Granite (Intrusive Igneous Rock)

Granite

Felsic intrusive igneous rock

Granite

Phaneritic Felsic Igneous Rock