Synthetic (Not A Natural Rock)

Sandstone

Sandstone (clastic sedimentary rock)

Granite

Granite (Felsic Plutonic Rock)

Sandstone

Arenite (SiO2 secondary)

Green Aventurine

Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Moonstone (bead form)

Potassium Aluminum Silicate (KAlSi3O8) - a variety of Orthoclase Feldspar

Iron-stained sandstone or weathered ironstone concretion

Quartz-rich sandstone, locally cemented by iron oxides (hematite/goethite); exact identification requires testing

Granite pebble

Granite, chiefly quartz, feldspar, and mica

Basalt with Scoria/Vesicular Texture

Vesicular Basalt (Iron-rich/Oxidized)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Amethyst Cluster

Silicon Dioxide (SiO2) with iron impurities

Smoky Quartz on Matrix

Silicon Dioxide (SiO2) with trace impurities and aluminum inclusions

Dyed Agate

Silicon Dioxide (SiO2) with artificial pigment

Riverstone Jasper (Chalcedony)

Silicon Dioxide (SiO2)

Shale with Siltstone layering

Sedimentary Clastic Rock (Mudstone/Shale)

Amethyst Geode (Carved)

Amethyst (Violet Crystalline Quartz - SiO2)

Weathered quartz-rich rock, possibly chert or quartzite fragment

Indeterminate; likely microcrystalline quartz (SiO₂), possibly with iron-oxide staining

Red Sandstone

Arenite (primarily Quartz and Iron Oxide)

Sandstone Concretion

Arenaceous concretion (primarily SiO2 with Fe2O3 staining)

Blue Sapphire (Tumbled/Polished)

Corundum (Al2O3)

Black Onyx

Silicon Dioxide (SiO2) with parallel banding

Purple Dyed Agate Geode (Banded Chalcedony)

Silicon Dioxide (SiO2) - variety: Agate

Black Pebble (Basalt / Chert)

SiO2 (if Chert) or Mafic Igneous Rock (if Basalt)

Hag Stone

Perforated Sedimentary Rock (primarily Siltstone or Mudstone)

Beach Pebble (Gray Quartzite / Fine-Grained Metasediment)

Quartzite (SiO2-dominated rock) / Metamorphic Sandstone

Granite

Granite (silica-rich intrusive igneous rock)

Pumice

Pumice (Vesicular Rhyolite/Andesite)

Likely weathered granite or granitic pegmatite

Granite; mainly quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining

Banded Agate

Microcrystalline Quartz (SiO2) with impurities

Red Sandstone

Arenite (Ferruginous Sandstone)

Amethyst

Amethyst (SiO2)

Oolitic Chert

Silicon Dioxide (SiO2) with oolitic texture

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Granite

Granite (Felsic Intrusive Igneous Rock)

Mixed polished gemstone bead lot, likely dyed agate and quartz

Chalcedony (microcrystalline quartz, SiO₂), with possible amethyst, aventurine, and other dyed quartz varieties

Tumbled dark gray stone, likely basalt

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, commonly with olivine

Sandstone

Sedimentary Rock (Quartz Arenite)

Granite

Granite (Phaneritic igneous rock)

Granite

Granite (Felsic Plutonic Rock)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)

Citrine

Citrine (Silicon Dioxide - SiO2)

Druzy Quartz Geode (with Chalcedony)

Silicon Dioxide (SiO2)

Quartz Crystal Cluster on Matrix

Silicon Dioxide (SiO2)