Pyrite and Quartz Agglomerate
Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)
mineral
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
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Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
sedimentary or metamorphic
Common Opal
Amorphous Hydrated Silica (SiO2·nH2O)
mineral
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (variations include Flint/Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Turquoise (possible Dyed Magnesite/Howlite)
CuAl6(PO4)4(OH)8·4H2O
mineral
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral
Baltic Amber (Butterscotch or Egg Yolk Variety)
Fossilized Tree Resin (Succinite); Approximate formula: C10H16O
Organic Gemstone (Succinite)
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
sedimentary
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
mineral
Shale
Shale (clay-sized silicate minerals)
sedimentary
Fossilized Chiton (Polyplacophora)
Polyplacophora (fossilized valves)
mineralized fossil
Fancy Jasper
Silicon Dioxide (SiO2) with iron and organic inclusions
sedimentary
Glauconite (Green Sandstone)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Hypersthene
Hypersthene (formula: (Mg,Fe)SiO3)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (and Limestone)
Chert (consisting of Microcrystalline Quartz, SiO2)
sedimentary
Quartz Mineral
Silicon dioxide (SiO2)
mineral
Bloodstone
Heliotrope (Chalcedony)
mineral
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Limonite-stained Chert
Microcrystalline Quartz (SiO2) with Hydrated Iron Oxides (FeO(OH)·nH2O)
sedimentary
Travertine (Tufa)
Chemical Limestone (CaCO3)
sedimentary
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Peridot (Olivine)
Olivine ((Mg, Fe)2SiO4)
mineral
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amazonite
Amazonite / Microcline (KAlSi3O8)
igneous
Septarian Nodule (Micro-fragment)
Septarian Nodule / Concretion (CaCO3 + CaMg(CO3)2 + Quartz)
sedimentary
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide with impurities (SiO2)
Mineral
Chrysocolla
Hydrated copper silicate - Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
mineral
Ironstone Concretion
Siderite or Hematite Concretion
sedimentary
Fossiliferous Siltstone
Clastic Sedimentary Rock with Fossil Inclusions
sedimentary
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
metamorphic
Blue Tiger's Eye (Hawks Eye)
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Moonstone (specifically Rainbow Moonstone / White Labradorite)
White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral