Sedimentary Or Igneous (Secondary Formation)

Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.

River Stone (River Pebbles)

Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)

sedimentary

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

sedimentary

Chert (often called Flint or River Rock)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

sedimentary

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Sedimentary

Fossil / Permineralized Bone

Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)

sedimentary

Chert (specifically Flint or Common Chert)

Microcrystalline Quartz (SiO2)

sedimentary

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Sedimentary

Picture Jasper

Silicon Dioxide (SiO2) with impurities

sedimentary

Ferruginous Sandstone

Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)

sedimentary

Jasper (specifically Red or Brecciated Jasper variant)

Jasper (Microcrystalline Quartz - SiO2)

sedimentary

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

sedimentary

Chert (Nodule)

Silicon Dioxide (SiO2)

sedimentary

Banded Onyx (Calcite Marble)

Calcite (CaCO3) - Trap-rock or Cave Onyx

sedimentary

Red Jasper

Jasper (SiO2 with Fe2O3 inclusions)

sedimentary

Geode with Quartz and possibly Jasper/Hematite

Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides

Mineral/Sedimentary Geode

Dalmatian Stone (Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

igneous

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

Mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Mineral

Blue Sapphire (Ceylon)

Corundum (Al2O3) with traces of Iron and Titanium

mineral

Banded Iron Formation

Banded Iron Formation (BIF)

Metamorphic Rock

Pyrite (on Shale/Matrix)

Iron Disulfide (FeS2)

mineral

Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

sedimentary

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)

Mineral

Diamond (in jewelry)

Carbon (C)

mineral

Black Pearl (Tahitian Type)

Aragonite / Conchiolin composite (CaCO3)

mineraloid

Gastly (Trick or Trade Halloween Series)

Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)

Mineral (Synthetic - Paper and Ink Polymorph)

Diamond

Diamond (pure Carbon, C)

mineral

Limonite and Goethite on Gossan

FeO(OH)·nH2O

mineral

Agate

Agate (Silicon Dioxide, SiO2)

mineral

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Mineral

Malachite

Copper(II) carbonate hydroxide [Cu2CO3(OH)2]

mineral

Chrysocolla in Cuprite (Sonora Sunrise)

Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O) with Cu2O

mineral

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

mineral

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Mineral

Milky Quartz

Quartz (SiO₂)

Mineral

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Sedimentary rock