Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
sedimentary
Category
Mineral, Organic Gemstone
Browse mineral, organic gemstone specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Aquamarine
Beryl (Be3Al2Si6O18)
mineral
Moonstone
Orthoclase feldspar ((K,Na)AlSi3O8)
mineral
Chert (Limestone-based)
Silicon dioxide (SiO2)
sedimentary
Chert / Flint
Chert (Silicon Dioxide, SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Banded Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Moonstone (Feldspar)
Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Black Marble
Recrystallized Calcite (CaCO3)
metamorphic
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Mineral/Fossil (Sedimentary context)
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2) with iridescent tarnish
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Moonstone (Orthoclase Feldspar)
(K,Na)AlSi3O8
mineral
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
sedimentary
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Amethyst (Quartz)
Silicon Dioxide (SiO2)
mineral
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Alexandrite in Matrix
Chrysoberyl (BeAl2O4 with Chromium impurities)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron Oxide)
metamorphic
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4 nH2O
mineral
Amazonite
Potassium Feldspar (KAlSi3O8)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
mineral
Chrysocolla
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·n(H2O)
mineral
Tektite (Indochinite)
Tektite (impactite), primarily high-silica glass (SiO2)
igneous
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
mineral
Epidote (likely Unakite component or Epidosite)
Epidote (Ca2(Al2Fe)(SiO4)(Si2O7)O(OH))
metamorphic
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Heliotrope (Bloodstone)
Silicon dioxide (SiO2) with inclusions
mineral
Emerald (Beryl)
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Charoite
K(Ca,Na)2Si4O10(OH,F)·H2O
metamorphic
Raw Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
mineral
Druzy Quartz on Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Amethyst variety)
Silicon Dioxide (SiO2)
mineral
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·n(H2O)
mineral
Amazonite
Potassium aluminum silicate (KAlSi3O8)
mineral
Carnelian
Carnelian (Silicon Dioxide, SiO2)
mineral