Shale
Shale (Sedimentary rock composed of mud/clay minerals)
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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Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Tumbled banded agate (likely chalcedony)
Microcrystalline quartz, SiO₂; probable banded chalcedony/agate
mineral
Likely garnet-bearing rock
Garnet in a dark metamorphic matrix; garnet is commonly almandine, Fe₃Al₂(SiO₄)₃
metamorphic
Amber
Succinates (Organic compound: C10H16O)
mineraloid
Amber (Dark/Black Variety)
Succinite (Resinite), C10H16O
mineral
Ironstone Concretion (Limonite/Goethite)
Goethite/Limonite concretion (FeO(OH)·nH2O)
sedimentary
Chert with Quartz Veins
Microcrystalline Quartz (SiO2)
sedimentary
Limestone (Tufa/Travertine)
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
sedimentary
Banded sandstone pebble
Quartz-rich lithic sandstone; exact provenance and composition require testing
sedimentary
Fossilized stromatolite or laminated microbial mat
Layered carbonate/chert fossil; exact taxon indeterminate from the image
fossil
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Graphite-bearing schist (probable)
Graphite schist; chiefly quartz, mica, and graphite
metamorphic
Emerald in Host Rock
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
mineral
Amethyst, Aquamarine, and Pearl Ring
SiO2 (Amethyst), Be3Al2Si6O18 (Aquamarine), CaCO3 (Pearl)
gemstone
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Petrified Wood
Silicified wood / Permineralized wood (SiO2)
fossil
Chert (specifically Brown Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Amber
Succinite (Fossilized Tree Resin)
gemstone
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Mineral
Chert / Chalcedony
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified wood (primarily Quartz, SiO2)
fossil
Carnelian agate
Cryptocrystalline quartz (SiO₂), iron-oxide-bearing chalcedony
gemstone
Chert Concretion (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (with Epidote/Quartz veining)
Cryptocrystalline silica (SiO2) with Epidote/Quartz inclusions
sedimentary
Green Quartz (Prasiolite/Adventurine)
Silicon Dioxide with inclusions (SiO2)
mineral
Pearl
Calcium carbonate (Aragonite/Calcite) - CaCO3
gemstone
Amber (fossilized tree resin)
Succinite; organic resin composed mainly of polymerized terpenoids
fossil
Moss Agate
Agate (Silicon Dioxide, SiO2) with dendritic inclusions
sedimentary
Chert (often called Flint or Jasper)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18)
mineral
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
mineral
Chakra Crystal Bracelet
Mixed Mineral Assortment
gemstone
![Fossilized bone fragment (probable mammalian tooth or bone) (Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite) — fossil](https://media.rock.id/fossilized-bone-fragment-probable-6435bbec-570b-407e-9c9f-870b904b8d23-thumbnail.jpg)
Fossilized bone fragment (probable mammalian tooth or bone)
Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Quartz Geode
Silicon Dioxide (SiO2) in sedimentary host rock
sedimentary