Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
sedimentary
Category
Organic Gemstone (Not A Rock Or Mineral)
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock Or Mineral) in the encyclopedia
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Carnelian and White Quartz Bracelet
Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz
mineral
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Tufa (Limestone)
Calcareous Tufa (CaCO3)
sedimentary
Chert Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Unakite
Epidotized Granite
metamorphic
Quartz Crystal (Amethyst)
Silicon Dioxide (SiO2)
mineral
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
sedimentary
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
sedimentary
Shale (possibly Carbonaceous or Oil Shale)
Laminated Mudstone (primarily clay minerals and quartz)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Chert (likely Flint or Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Chert with Quartz Veining
Silicon Dioxide (SiO2)
sedimentary
Red Jasper
SiO2 (Silicon Dioxide with Hematite inclusions)
mineral
Tiger's Eye
Silicon dioxide (SiO2) - Pseudomorph after crocidolite
mineral
Gemstone Tree Brooch (Agate and Quartz)
Silicon Dioxide (SiO2)
mineral
Pearl
Calcium carbonate (Aragonite/Calcite) - CaCO3
gemstone
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Bivalve Fossil (Fossilized Shell)
Class Bivalvia (fossilized in Calcium Carbonate/Aragonite)
fossil
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Clear Quartz
SiO2 (Silicon Dioxide)
mineral
Amber (Copal)
Succiniferous Resin
mineraloid
Pyrite
Pyrite (FeS2)
Mineral
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
sedimentary
Petrified Wood
Silicon Dioxide (SiO2)
fossil
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
sedimentary
Petrified Wood
Silicified wood (principally SiO2)
sedimentary
Jasper (Brown Iron-Rich Variety)
Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)
sedimentary
White Topaz
Aluminum Silicate Fluoride Hydroxide; Al2SiO4(F,OH)2
mineral
Sandstone
Arenite
sedimentary
Geode Nodules / Keokuk Geode
Quartz / Chalcedony Geode (SiO2)
sedimentary
Travertine (Tufa)
Chemical Sedimentary Rock / Travertine (CaCO3)
sedimentary
Emerald with Matrix (Emerald in Mica Schist)
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Fossil Shark Tooth
Chondrichthyes tooth fossil
fossil
Pink Opal
Hydrated Silica (SiO2·nH2O) with Palygorskite/Sepiolite inclusions
gemstone
Travertine (Tufa)
Chemical Limestone (CaCO3)
sedimentary
Ironstone Concretion (Boxwork)
Siderite-Limonite Concretion (FeO(OH)·nH2O)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral