Peridotite (Dunite)
Peridotite (mostly Olivine: (Mg,Fe)2SiO4)
igneous
Category
Sedimentary (With Some Aspects Of Mineral Replacement)
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Greenstone (Greenschist)
Greenschist (composed of Chlorite, Epidote, and Actinolite)
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron Oxide inclusions)
metamorphic
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Ironstone (likely Ferruginous Siltstone/Sandstone)
Ferruginous sedimentary rock (FeOx-rich clastic)
sedimentary
Fossiliferous Limestone
Calcareous biomicrite / Bioclastic limestone
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
sedimentary
Yellow Jasper (Beach Pebble)
Silicon Dioxide (SiO2) with iron hydroxide impurities
sedimentary
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Red Jasper (Plum or Brick variety)
Silicon Dioxide (SiO2) with iron oxide inclusions (Hematite)
sedimentary (chemical/biological origin)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Mineral
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Sedimentary
Cobaltian Calcite
Cobalt-bearing Calcite (Ca,Co)CO3
mineral
Ferruginous Conglomerate
Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))
sedimentary
Quartz (Float/Abraded)
Quartz (SiO₂)
Mineral
Gneiss (Metamorphic Rock)
Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)
metamorphic
Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Crinoid Columnal Fossil
Class Crinoidea (Echinodermata); usually calcite replacement (CaCO3)
sedimentary
Tiger's Eye (and Hematite/Jasper Matrix)
SiO2 (Pseudomorph of Quartz after Crocidolite) with Hematite/Magnetite
mineral
Tiger's Eye (Rough)
Macrocrystalline Quartz (SiO2 with inclusions of Crocidolite)
mineral
Conglomerate
Conglomerate
Sedimentary Rock
Fossiliferous Limestone (Crinoidal)
Calcium Carbonate (CaCO3) - Limestone containing bioclasts
sedimentary
Oolitic Chert
Silicon Dioxide (SiO2) with oolitic texture
sedimentary
Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Schist (specifically Chlorite/Greenschist)
Chlorite Schist
metamorphic
Granite Gneiss
Gneiss (derived from granitic protolith)
metamorphic
Ferruginous Sandstone
Sandstone, Iron-rich
sedimentary
Pyrite
Iron Pyrite (FeS₂)
Mineral
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (C10H16O)
Organic Gemstone (fossilized resin)
Hematite
Hematite (Fe2O3)
mineral
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
mineral
White Quartz (Milky Quartz Mushroom)
Silicon Dioxide (SiO2)
mineral