Metamorphic Rock (Specifically A Rock Composed Of Minerals)

Quartzite

Quartzite (composed primarily of SiO2)

Serpentine

Antigorite, Lizardite, or Chrysotile (Mg3Si2O5(OH)4)

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Unakite

Altered Granite (Epidote, Orthoclase Feldspar, Quartz)

Sandstone

Arenite (composed primarily of SiO2)

Granitic Pegmatite

Granite Pegmatite (coarse-grained intrusive igneous rock)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Red Sandstone

Arenite (primarily Quartz with Iron Oxide coating)

Weathered Sandstone or Siltstone

Sedimentary Rock

Gravel / Crushed Stone

Aggregate (mixed mineral rock fragments)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals such as Antigorite, Lizardite, and Chrysotile)

Red Sandstone

Ferruginous Sandstone (SiO2 with Fe2O3)

Quartzite

Quartzite (SiO2 silicon dioxide)

Granite

Phaneritic Felsic Igneous Rock

Quartzite

Quartzite (composed primarily of SiO2)

Vesicular Basalt

Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)

Botryoidal Chalcedony (Agate)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Clastic Sedimentary Rock (Sandstone)

Granite

Granite (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Unidentifiable Rock Fragment

Dark green metamorphic rock, likely serpentinite

Serpentinite, composed mainly of serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and minor chlorite/talc

Sandstone

Clastic sedimentary rock (primarily SiO2)

Gneiss

Gneiss (Metamorphic Rock)

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Granite / Quartzite Specimen

Granite / Quartz (SiO2 with Feldspar and Mica)

Granite

Phaneritic plutonic rock (approx. 20-60% quartz, 35-90% feldspar)

Generic Rock Fragment

Rock Fragment

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite)

Gneiss

Gneiss (Metamorphic rock)

Granite

Granite (Felsic Plutonic Rock)

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

Bauxite (Iron-stained Chert / Ironstone Aggregate)

Hydrous aluminum oxide mixture (mainly Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Goethite α-Fe3+O(OH))

Bauxite

Bauxite (Al2O3·2H2O)

Bumblebee Jasper

Carbonate-rich volcanic rock containing Sulfur and Arsenic (Realgar/Orpiment)

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Yellow Jasper

Silicon Dioxide (SiO2 with iron oxide inclusions)

Granite

Intrusive Igneous Rock

Polished pegmatitic granite (likely graphic granite)

Coarse-grained granitic rock composed chiefly of quartz, feldspar, and biotite/hornblende

Quartzite

Quartzite (composed primarily of SiO2)

Banded Gneiss

Gneiss (Metamorphic Rock)

Serpentinite

Serpentinite (composed largely of serpentine group minerals including Antigorite, Lizardite, or Chrysotile)

Unakite Epidote Granite

Unakite (Rock composed of Orthoclase, Epidote, and Quartz)