Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Category
Sedimentary Or Metamorphic
Browse sedimentary or metamorphic specimens identified by the Rock Identifier community.
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Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Metamorphic Rock
Feldspar-rich Quartzite
Metamorphic Quartz-Feldspar Aggregate (SiO2 + KAlSi3O8)
metamorphic
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Pyrite (or Fool's Gold)
Pyrite (FeS₂)
Mineral
River Stone / Pebble
Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)
Mineral, Sediment
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
sedimentary and metamorphic
Jasper
Chalcedony (Microcrystalline Quartz) - SiO2
sedimentary or metamorphic
Sandstone, Quartzite, and River Pebbles
Silicon Dioxide (SiO2) based Sedimentary/Metamorphic structures
Sedimentary and Metamorphic
Mixed Agate and Lapis Lazuli Bracelet
Chalcedony (SiO2) and Lapis Lazuli (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
sedimentary and metamorphic
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
sedimentary or metamorphic
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
sedimentary or metamorphic
Jasper and Quartzite mix
Silicon Dioxide (SiO2) with impurities
sedimentary or metamorphic
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
sedimentary or metamorphic
Red Jasper (possibly with Quartz or Hematite)
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary or metamorphic
River Pebbles (Sandstone and Quartzite)
SiO2 (Quartz) dominated clastic rocks
sedimentary and metamorphic
Micaceous Sandstone or Quartzite
Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)
Sedimentary or Metamorphic
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2) crystal conglomerate
sedimentary or metamorphic
Unidentified River Rock or Mudstone
N/A (Generic rock fragment)
Sedimentary or Metamorphic
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Mineral
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Mineral
Drill Core Samples (Varied Lithology)
Multi-lithological core samples (containing potential granite, marble, and phyllite/schist sequence)
igneous, sedimentary, and metamorphic
Mixed collection of minerals and rocks (Jasper, Carnelian, Granite, and Quartz)
Silicon Dioxide (SiO2) with varying impurities for silicates and igneous aggregates
igneous, sedimentary, and metamorphic
Engineer Quartz/Quartzite
SiO2 (Silicon Dioxide with binders)
Sedimentary or metamorphic-derived
Mixed Tumbled Stones (Mostly Agate, Jasper, and Quartz)
Silicon Dioxide (SiO2)
sedimentary and metamorphic minerals
Earth
Terra / Earth
igneous, sedimentary, and metamorphic
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Painted River Rock
Polished fluvial clast with acrylic/synthetic pigment coating
Sedimentary or Metamorphic (base substrate)
Crushed Stone / Gravel (Multiple Rock Types)
Lithic fragments (undifferentiated)
Igneous, Sedimentary, and Metamorphic mix
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
igneous, sedimentary, or metamorphic (mineral-based)
Green Slag Glass (Cullet)
Amorphous Silica (Industrial Glass Byproduct)
Synthetic/Byproduct (Non-igneous, non-sedimentary, non-metamorphic)
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
mineral
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
mineral
Kyanite
Kyanite (Al2SiO5)
mineral
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3)
metamorphic
Garnet Schist
Almandine Garnet Schist (Fe3Al2(SiO4)3 in Schistose matrix)
metamorphic