Basalt

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide) primarily colored by iron oxide (Hematite)

Amethyst

Amethyst (Silica mineral, SiO2)

Bauxite

Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Sunstone

Plagioclase Feldspar (Na, Ca)(Al, Si)4O8 with Hematite or Copper inclusions

Agate (translucent slice)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Carnelian

Carnelian (Silicon Dioxide, SiO2)

Vesicular Basalt (Scoria)

Mafic extrusive igneous rock (primarily Plagioclase Feldspar and Pyroxene)

Scoria (Vesicular Basalt)

Scoria (Extrusive Igneous Rock)

Olivine in Basalt (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt

Scoria (Vesicular Basalt)

Scoria (Extrusive Igneous Rock)

Amethyst (Quartz Cluster)

Silicon Dioxide (SiO2) with iron impurities

Peridot

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Quartz Geode

Silicon Dioxide (SiO₂)

Apache Tear

Obsidian (Hydrated Silica Rich Volcanic Glass)

Agate (Moss or Banded Agate variety)

Agate (Silicon Dioxide - SiO2)

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities

Bauxite (Pisolitic Bauxite)

Bauxite (mixture of Hydrous Aluminum Oxides)

Labradorite (a variety of Anorthosite or Plagioclase)

Labradorite (member of Plagioclase Feldspar series), (Ca,Na)(Al,Si)4O8

Agate

Chalcedony (SiO2)

Smoky Quartz and Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)

Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein

Carnelian (Orange Chalcedony)

Silicon Dioxide (SiO2) - variety of Chalcedony

Blue Lace Agate (with Amethyst Geode center)

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Granite (Pegmatitic)

Phaneritic Felsic Igneous Rock

River Cobble (likely Basalt)

Mafic Igneous Rock (Aphanitic)

Zebra Jasper (usually a trade name for Serpentine or Basalt blend)

Antigorite/Chrysotile (Serpentine family) - Mg3Si2O5(OH)4

Scoria (Lava Rock)

Scoria (Vesicular Basaltic Rock)

Scoria

Scoria (Vesicular Basaltic Glass)

Scoria (Red Lava Rock)

Scoria (Vesicular basaltic rock)

Scoria (Volcanic Rock)

Scoria (often basaltic scoria)

Scoria

Vesicular Basaltic Andesite/Scoria

Granite Pebble (Salt and Pepper Granite)

Felsic Intrusive Igneous Rock (Granite)

Porphyritic Basalt (with Quartz or Calcite inclusion)

Porphyritic Basalt (Matrix: SiO2/MgO/FeO, Phenocryst: likely Quartz or Calcite)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Carnelian Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Amethyst (Cabochon)

Silicon Dioxide (SiO2) with iron impurities

Epidote in Matrix

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Amethyst (Tumbled Stone)

Amethyst (Silicon Dioxide with Iron impurities, SiO2)