Not A Natural Rock (Man Made Composite)

Quartz Pebble

Silicon Dioxide (SiO2)

Citrine

Silicon dioxide (SiO2)

Diamond

Carbon (C)

Citrine Quartz

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2)

Milky quartz pebble

Quartz (SiO₂), commonly called milky quartz

Diamond

Native Carbon (C)

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone (with Moss/Lichen Growth)

Sandstone (Quartz Arenite / Lithic Arenite)

Citrine Geode

Citrine (Silicon Dioxide, SiO2)

Sodalite beads

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, likely with minor lazurite/pyrite or calcite inclusions

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Tumbled white quartz or quartzite pebble

Quartz (SiO₂), possibly massive quartzite

Faceted blue gemstone, likely blue topaz or synthetic spinel

Topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); image insufficient for certainty

Quartz (Golden Quartz / Citrine / Iron-stained Quartz)

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon dioxide (SiO2)

Selenite (gypsum)

Gypsum, CaSO₄·2H₂O; variety commonly called satin spar or selenite

Smoky Quartz

Silicon Dioxide (SiO2)

Blue Howlite (Dyed)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Dyed pink agate slice

Agate (microcrystalline quartz, SiO₂), commonly chalcedony with artificial dye

Prasiolite (Green Quartz) / Sea Glass Amalgam

SiO2 (Silicon Dioxide)

Tumbled yellow chalcedony (likely citrine or yellow jasper)

Microcrystalline quartz, SiO₂; exact identification is uncertain from the photograph

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides

Citrine

Silicon Dioxide (SiO2) with ferric iron impurities

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Sandstone

Arenite

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone (Quartz Sandstone)

Arenite (SiO2 based)

Smoky Quartz

Silicon Dioxide (SiO2)

Metallic sulfide mineral fragment, likely bornite or chalcopyrite

Bornite (Cu₅FeS₄) or chalcopyrite (CuFeS₂)

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Tumbled citrine quartz (likely heat-treated amethyst)

Quartz, SiO₂; crystalline variety citrine

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone Pebble

Arenite (SiO2 with various cementing agents)

Quartz (Citrine or Iron-Stained)

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)