Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
sedimentary
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Pyrite in Shale
Iron Disulfide (FeS2)
mineral
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Chert Pebble (Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Yellow Jasper
Tectosilicates (SiO2) with Goethite/Iron oxide inclusions
sedimentary
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Mineral (Organic Gemstone)
Chert (Commonly known as Flint or Jasper when pigmented)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (with formula approximately C10H16O)
Organic mineraloid
Fluorite
Calcium Fluoride (CaF2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Ruby in Zoisite
Ruby (α-Al2O3) embedded in Zoisite (Ca2Al3(SiO4)3(OH)) with some Hornblende
Metamorphic Rock (composed of multiple minerals)
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (Iron-rich variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
sedimentary
Amber Inlay Jewelry
Fossilized Resin (C10H16O)
Organic Gemstone (Biogenic)
Native Gold
Native Gold (Au)
mineral
Yellow Chalcedony (common opal or chert variant)
Silicon Dioxide (SiO2)
sedimentary (mineraloid/microcrystalline quartz)
Gold Nugget
Native Gold (Au)
mineral
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
mineral
Gneiss (specifically Banded Gneiss)
Gneiss
metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Amber (specifically Cherry Amber)
Succinite (with the chemical formula C10H16O)
Organic Gemstone (not a mineral)
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Yellow Agate
Chalcedony (cryptocrystalline silica), SiO2
mineral
Staurolite (Fairy Stone)
Staurolite (Fe2+2Al9Si4O23(OH))
metamorphic
Greenstone
Greenschist (commonly containing Chlorite, Actinolite, and Epidote)
metamorphic
Chert (Green variety)
Microcrystalline Opaline/Quartz (SiO2)
sedimentary
Red Jasper
Jasper (SiO2) - Silicon Dioxide with Hematic impurities
sedimentary
Chert / Flint
Cryptocrystalline Quartz (SiO2)
sedimentary
Fluorite
Calcium Fluoride (CaF2)
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Epidote
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
metamorphic
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides
sedimentary