Milky Quartz
Silicon Dioxide (SiO2)
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Milky Quartz
Silicon Dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide impurities), formula: SiO2
Silver Sheen Obsidian
Volcanic Glass (Amorphous Silicon Dioxide - SiO2 with impurities)
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Granitic Pegmatite with Schorl Tourmaline
Granitic Pegmatite (Schorl: NaFe3Al6(BO3)3Si6O18(OH)4)
Pegmatite
Granitic Pegmatite
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Dalmatian Stone (Dalmatian Jasper)
Peralkaline Quartz-Feldspar Rock with Arfvedsonite
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Quartz Geode (Unbroken)
Silicon Dioxide (SiO2)
Septarian Nodule (Septarian Stone)
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Iron Oxide impurities)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Bog Iron / Limonite Concretion
Goethite/Limonite mixture (FeO(OH)·nH2O)
Jasper
Silicon Dioxide (SiO2)
Geode (Quartz chalcedony variety)
SiO2 (Silicon Dioxide)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides
Chert (Blue-Gray Chert)
Microcrystalline quartz (SiO2)
Jasper
Jasper (Cryptocrystalline Quartz; SiO2)
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
Aquamarine
Beryllium Aluminum Silicate (Be3Al2Si6O18)
Chert (with Iron Staining)
Silicon Dioxide (SiO2)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within metamorphic/igneous matrix
Chert (variously known as Flint or River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Shale
Shale
Quartz Sand Grain
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Milky Quartz (among River Rock)
Quartz (Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Opal
Hydrous silicon dioxide (SiO2·nH2O)
Red Garnet
Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)
Gypsum (Satin Spar/Desert Rose variety)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Dyed Agate Geode (Pink/Magenta)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Chert (specifically a weathered Chert nodule or fragment)
Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)
Garnet (likely Almandine)
Almandine (Fe3Al2(SiO4)3)
Epidote-bearing Granite (Unakite-like)
Epidotized Granite
Amber (Cherry Amber)
Succinite (C10H16O)
Banded Calcite (often sold as Onyx Marble)
Calcite (Calcium Carbonate, CaCO3)