Pebble (Likely Basalt or Siltstone)
Clastic sedimentary rock or mafic volcanic rock
Igneous or Sedimentary
Category
Sedimentary And Igneous (Mixed)
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
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
Pink Opal / Peruvian Opal
Hydrated amorphous silicon dioxide (SiO2·nH2O)
Mineral
Quartz Pebble
Silicon Dioxide (SiO2)
Mineral / Sedimentary
Apatite
Apatite Group (e.g., Fluorapatite Ca5(PO4)3F, Chlorapatite Ca5(PO4)3Cl, Hydroxylapatite Ca5(PO4)3(OH))
mineral
Rock Crystal Quartz
Quartz (SiO₂)
Mineral
Nephrite Jade
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
Mineral
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Crystal Quartz Beads (likely Clear Quartz)
Quartz (SiO₂)
Mineral
Fluorite in Matrix
Fluorite (CaF2) within a host rock matrix
Mineral
Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Gneiss
Gneiss (Metamorphic rock of variable composition, typically SiO2 rich)
metamorphic
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)
Mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)
Silicon Dioxide (SiO2) or Mafic extrusive igneous rock
sedimentary or igneous
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
Citrine
Quartz (SiO₂)
mineral
River Cobble (likely Basalt or Chert)
Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous
igneous/sedimentary
Muscovite Mica
Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2
mineral
Laterite
Laterite (no specific mineral formula as it's a rock type)
Sedimentary
Obsidian and Green Calcite
Volcanic Glass and Calcium Carbonate (CaCO3)
igneous and sedimentary/mineral
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Sandstone (Pebble/Cobble)
Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)
Sedimentary
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mineral
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Quartz
Silicon Dioxide (SiO2)
Mineral
Peridot and Citrine Gemstones (in a ring setting)
Peridot (Olivine: (Mg,Fe)2SiO4), Citrine (Quartz: SiO2)
mineral
Quartz (likely milky/gray variety)
Quartz (SiO₂)
Mineral
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Mineral
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Mineral
Quartz
Silicon Dioxide (SiO2)
Mineral
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Metamorphic Rock
River Pebbles (Sandstone and Quartzite)
SiO2 (Quartz) dominated clastic rocks
sedimentary and metamorphic
Sandstone, Quartzite, and River Pebbles
Silicon Dioxide (SiO2) based Sedimentary/Metamorphic structures
Sedimentary and Metamorphic
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Quartz
Quartz (SiO₂)
Mineral
Gold
Aurum (Elemental Gold, Au)
Mineral, Metal (element)
Banded Rock (likely Quartz-rich)
Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals
Mineral
Gneiss (Metamorphic Rock)
Gneiss
metamorphic
Mica (likely Muscovite)
Muscovite / KAl2(AlSi3O10)(OH)2
mineral
Magnetite
Magnetite (Fe3O4)
Mineral