Quartzite
Quartzite (primarily SiO2)
Metamorphic
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Tiger's Eye and Carnelian Quartz
Silicon Dioxide (SiO2)
metamorphic and mineral
Chert (Beach Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Sodalite
Na8(Al6Si6O24)Cl2 (Sodalite)
mineral
Anthracite Coal
Anthracite (Carbon based fossil fuel)
metamorphic
Chert (specifically Jasper/Flint pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
sedimentary
Picasso Jasper (or Picasso Marble)
Metamorphosed Limestone (Calcium Carbonate, CaCO3, with impurities)
metamorphic
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
igneous
Brown Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (varietal Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Asphalt
Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)
Sedimentary
Carnelian (Chalcedony variety)
SiO2 (Silicon Dioxide)
Mineral
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
sedimentary
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
igneous
Green Porphyry (Flowerstone)
Porphyritic Andesite or Basalt
igneous
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous Phosphate of Copper and Aluminum)
mineral
Baroque Pearl (and potentially a small Sapphire/Blue Topaz)
Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.
Organic Gemstone (for pearl), Mineral (for sapphire/topaz)
Lapis Lazuli
Lapis Lazuli (Aggregate primarily of Lazurite: (Na,Ca)8(AlSiO4)6(S,SO4,Cl,1-2) with Calcite and Pyrite)
metamorphic
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
sedimentary/mineral
Greenschist (Greenstone)
Greenschist (Metamorphic rock containing chlorite, actinolite, and epidote)
metamorphic
Pyrite
Iron Disulfide (FeS2)
mineral
Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Carnelian
Silicon dioxide (SiO2) with iron oxide impurities
mineral
Jasper (Tumbled)
Silicon Dioxide (SiO₂)
sedimentary (cryptocrystalline quartz)
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
igneous
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
igneous
Anthracite Coal
Anthracite
metamorphic
Amber
Succinite (fossilized tree resin)
mineral
Chert (Jasper variety) with Iron Oxide staining
Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities
sedimentary
Amber (Rough)
Amber (Fossilized Tree Resin, succinite)
mineral
Schist
Schist (various compositions)
metamorphic
Jasper (Red)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinite (Fossilized Resin)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Jasper (specifically Red Jasper/Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Amber
Succinite (specifically for Baltic amber); Approximate formula: C10H16O
Organic Gemstone (Mineraloid)
Diorite (Salt and Pepper Rock)
Diorite
igneous
Lapis Lazuli
Lapis Lazuli (Primary mineral: Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic