Milky and Citrine-type Quartz
Silicon Dioxide (SiO2)
mineral
Category
Tektite (Natural Glass)
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Onyx (Black Onyx)
Onyx (Silicon Dioxide, SiO2)
mineral
Sandstone
Arenite (SiO2 based clastic rock)
sedimentary
Golden Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
sedimentary
Clear Quartz
Silicon dioxide (SiO2)
mineral
Quartzite
Quartzite (primarily SiO2)
Metamorphic
Chevron Amethyst
Silicon Dioxide (SiO2) with trace Iron impurities
mineral
Amethyst
Quartz (Silicon Dioxide, SiO2) with iron impurities
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Orange Quartz (Citrine Quartz variety)
Silicon Dioxide (SiO2)
mineral
River Quartzite or Chert Pebble
Quartzite (primarily Silicon Dioxide - SiO2)
metamorphic
Amber (and Citrine Quartz)
Succinite (Amber) and Silicon Dioxide (SiO2)
Organic Mineraloid and Mineral
Mixed Quartz and River Pebbles (Stone Collection)
Mixed assortment containing mainly Silicon Dioxide (SiO2)
igneous, sedimentary, metamorphic, and mineral
Blue Topaz
Al2SiO4(F,OH)2 (Fluorine-bearing aluminum silicate)
mineral
Yellow Quartz (Chalcedony/Citrine Pebble)
Silicon Dioxide (SiO2)
mineral
Smoky Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Pumice
Pumicite (Amorphous Volcanic Glass)
igneous
Pumice
Pumice (volcanic glass with vesicular texture)
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Banded Quartzite River Pebble
Metamorphosed Quartz-rich Sandstone (SiO2)
metamorphic
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3/FeO(OH) cementing agents)
sedimentary
Yellow Quartz
Silicon Dioxide (SiO2)
mineral
Chert (Field-collected Arrowhead-shaped Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz (Variety: Rose Quartz/Smoky Quartz mix)
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
Mineral
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities and natural radiation
mineral
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Rough Sapphire (Corundum)
Corundum (Al2O3)
mineral
Clear Quartz (Crystal Quartz)
Silicon Dioxide (SiO2)
mineral
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Igneous
Synthetic Sapphire and Ion-X Glass
Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass
mineral
Diamond
Cubic Carbon (C)
mineral
Pink Quartzite
Metamorphosed Quartz Arenite (SiO2)
metamorphic
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral