Pyrite
Pyrite (Iron sulfide, FeS₂)
mineral
Category
Sedimentary (Alluvial Deposit)
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
Nephrite Jade
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
Mineral
Jasper, possibly Brecciated Jasper or Ocean Jasper due to patterns and color
Silicon Dioxide (SiO2), a variety of Chalcedony
Sedimentary Rock
Smoky Quartz
SiO2 (Silicon Dioxide)
Mineral
Sulfur on Aragonite
Sulfur (S) and Aragonite (CaCO3)
Mineral
Banded River Rock / Gneiss (highly weathered)
Gneiss
Metamorphic rock
Hematite Beads
Hematite (Fe2O3)
Mineral
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Mineral, often found in sedimentary deposits
Selenite
Gypsum (CaSO4·2H2O), specifically the crystalline variety Selenite
Mineral
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Mineral, specifically a rock fragment
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Mineral
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Sedimentary Rock (specifically a clastic sedimentary rock formed into a cobble)
Pumice
Pumice (volcanic rock)
Igneous
Banded Gneiss
Gneiss (pronounced "nice")
Metamorphic Rock
Quartz
Silicon Dioxide (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
Mica Group Minerals
There isn't a single scientific name as 'Mica' refers to a group of phyllosilicate minerals. Common scientific names include Muscovite (KAl₂ (AlSi₃O₁₀)(OH)₂), Biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH)₂), Phlogopite (KMg₃AlSi₃O₁₀(OH)₂), and Lepidolite (K(Li,Al)₃(Al,Si,Rb)₄O₁₀(F,OH)₂).
Mineral
Calcite
Calcite (CaCO3)
Mineral
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Metamorphic Rock
Banded Agate (likely Carnelian Agate or Sardonyx)
Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.
Sedimentary Rock (technically a variety of Chalcedony)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Laterite
Laterite (primarily composed of hydrated oxides of iron and aluminum)
Sedimentary Rock (as a residual soil/rock, it's often considered a type of sedimentary rock due to its formation from weathering, though it can cross into soil science)
Calcite (or Alabaster, if truly carved)
Calcium Carbonate (CaCO3)
Mineral/Rock
Gold Nugget
Native Gold (Au)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Sunstone (variety of Feldspar)
Oligoclase Sunstone, Plagioclase Feldspar (Na,Ca)Al(Si,Al)Si2O8
Mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Chalcedony (Moonstone-like Agate)
Silicon Dioxide (SiO₂)
mineral
Chalcedony (Agate/Carnelian type)
Silicon Dioxide (SiO2)
mineral
Chalcedony (Tumbled)
Silicon Dioxide (SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Carnelian
Carnelian (Silicon Dioxide - SiO2)
mineral
Agate
Banded Chalcedony (SiO2)
mineral
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
mineral
Red Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Grey Chalcedony (Tumbled Moon)
Microcrystalline Quartz (SiO2)
mineral
Jasper
Silicon dioxide (SiO2) with iron oxide impurities
sedimentary
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
sedimentary
Yellow Chalcedony (Agate/Chert)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Chalcedony (Agate/Chert)
Silicon Dioxide (SiO2)
mineral