Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Fluorite
Calcium Fluoride (CaF2)
mineral
Chert (v. Flint)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Pyrope Garnet (Bohemian Garnets)
Pyrope (from the group Mg3Al2(SiO4)3)
mineral
Scoria (Lava Rock)
Vesicular Basalt / Scoria
igneous
Yellow Quartz (Citrine or Yellow Chalcedony)
Silicon Dioxide (SiO2)
mineral
Quartz (Grain/Fragment)
Silicon Dioxide (SiO2)
mineral
Fossiliferous Limestone (Coquina / Shell Limestone)
Bioclastic Limestone (CaCO3)
sedimentary
Chalcedony (Yellow Agate/Chert)
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
sedimentary
Petrified Wood (Calamites Fossil)
Calamites sp. (Silicified/Permineralized Plant Fossil)
sedimentary
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Chert (containing Iron Oxide spots)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with goethite or iron oxide inclusions
sedimentary
Tektite (Indochinite)
Tektite (Silica-rich natural glass)
mineral
Porphyry
Porphyritic Andesite/Dacite
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules
igneous
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
metamorphic
Dalmatian Stone
Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite
igneous
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granite (weathered/river-tumbled)
Granite (Plutonic Igneous Rock)
Igneous Rock
Chert / Flint (with Crinoid Stem Molds)
Microcrystalline Quartz (SiO2)
sedimentary
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
mineral
Fossiliferous Chert (with Fossil Shells)
Silicon Dioxide (SiO2) with biogenic inclusions
sedimentary
Green Jasper (with Quartz veining)
Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2
sedimentary
Mica Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
mineral
Amber
Succinite (fossilized tree resin)
Organic Mineraloid
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
mineral
Epidote
Epidote Group (e.g., Clinozoisite, Epidote, Piemontite), Epidote formula: Ca2(Al,Fe)3(SiO4)3(OH)
Mineral
Lepidolite Bracelet
Lepidolite (K(Li,Al)3(Si,Al)4O10(F,OH)2) often in Quartz matrix
Mineral
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Mineral, specifically a Cryptocrystalline Quartz variety
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Chert (Jasper/Chalcedony variety)
Silicon Dioxide (SiO2)
sedimentary
Limonite (Iron Ore)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
mineral
Quartz Vein with Iron Staining
Silicon Dioxide (SiO2)
mineral