Sand
Siliciclastic sediment / Quartz sand (SiO2)
sedimentary
Category
Mineral Composite
Browse mineral composite specimens identified by the Rock Identifier community.
Learn about Mineral Composite in the encyclopedia
View all →
Pegmatite with Tourmaline
Pegmatite / Silicate
igneous
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Quartz-rich rock, likely granite or quartz-bearing metamorphic rock
Undetermined; possibly granitic rock composed mainly of quartz and feldspar, with mica or other dark minerals
igneous
Sandstone
Clastic Sedimentary Rock
sedimentary
Feldspar
Feldspar Group (Tectosilicate, e.g., KAlSi3O8)
mineral
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Limonite
FeO(OH)•nH2O
mineral
Unidentified pink-and-gray mineral or rock specimen
Undetermined; the image is too blurry for reliable identification
mineral
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Unidentified coarse-grained rock fragment, possibly granite
Possible granite: quartz, feldspar, and dark mica or amphibole; identification is uncertain from the image
igneous
Pegmatite with Tourmaline
Igneous Pegmatite (Quartz-Feldspar matrix with Schorl Tourmaline)
igneous
Gneiss
Gneiss
metamorphic
Shark Tooth Fossil
Carcharocles megalodon or similar extinct shark tooth
fossil
Mineral Sand (Heavy Mineral Sand Concentrate)
Placer deposit concentrate containing minerals such as ilmenite, rutile, zircon, and magnetite
mineral
Granite
Intrusive Igneous Rock
igneous
Calcite–fluorite mineral specimen with iron-oxide staining
Calcite (CaCO₃), likely fluorite (CaF₂), with possible quartz and iron/manganese oxides
mineral
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Limonite
FeO(OH)·nH2O
mineral
Marcasite Sun
Marcasite (FeS2)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Chakra Crystal Bracelet
Mixed Mineral Assortment
gemstone
Small brown mineral fragment (undetermined)
Unidentified; image detail is insufficient for a reliable species identification
mineral
Bauxite
Bauxite (principal ore of aluminum, primarily Al(OH)3)
sedimentary
Bauxite (Laterite)
Hydrated aluminum oxides (Al2O3·nH2O)
sedimentary
Schist
Schist
Metamorphic
Limonite
FeO(OH)•nH2O
mineral
Limonite
FeO(OH)•nH2O
mineral
Yellow serpentine (likely serpentine-rich rock)
Serpentinite; chiefly serpentine-group minerals, such as antigorite, lizardite, and chrysotile
metamorphic
Granite
Intrusive Igneous Rock
igneous
Banded gneiss pebble
Gneiss, a foliated metamorphic rock composed mainly of quartz, feldspar, and dark biotite or amphibole
metamorphic
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Sandstone
Sedimentary Clastic Rock
sedimentary
Blue-green rough mineral specimen (identity uncertain)
Undetermined; the image is insufficient for a reliable mineral identification
mineral
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Topaz
Al2SiO4(F,OH)2
mineral