Quartz Pebble
Silicon Dioxide (SiO2)
Category
Browse mineral (tectosilicate) specimens identified by the Rock Identifier community.
Quartz Pebble
Silicon Dioxide (SiO2)
Mica (Muscovite or Biotite)
Sheet silicate mineral group (e.g., KAl2(AlSi3O10)(F,OH)2)
Feldspar
Aluminosilicate (KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Vesicular basalt (likely weathered lava rock)
Vesicular basalt; primarily plagioclase feldspar, pyroxene, and volcanic glass, with possible iron-oxide alteration
Banded Gneiss
Gneiss (Foliated Metamorphic Rock)
Granite
Granite (composed mainly of Quartz, Potassium Feldspar, Plagioclase, and Biotite/Mica)
Gneiss (specifically Granite Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
Gneiss
Metamorphic Foliated Gneiss
Limonite
FeO(OH)·nH2O
Small quartz-rich mineral fragment
Quartz (SiO₂), possibly milky or chalcedonic quartz
Greenstone / Metabasalt
Chlorite schist or Epidiorite
Greenstone
Protolith: Basaltic rock
Greenstone
Greenschist / Meta-basalt
Granite
Intrusive Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Limonite Geode / Ironstone Nodule
Hydrated Iron Oxide Hydroxide (FeO(OH)·nH2O)
Turquoise and Hematite
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Hematite (Fe2O3)
Sandstone
Arenite (SiO2 principal composition)
Weathered, quartz-rich metamorphic rock (likely schist or gneiss)
Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining
Banded Gneiss Pebble
Gneiss (Metamorphic Rock)
Petrified Wood / Fossilized Wood
Silicified Wood (Silicon Dioxide - SiO2)
Quartz with Calcite
Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3)
Copper Ore (Malachite and Limonite bearing)
Cuprite, Malachite, and Limonite mixture
Banded Iron Formation (Fragment)
Banded Iron Formation (BIF)
Calcite (Honey Calcite and Agate)
Calcium Carbonate (CaCO3)
Yellow Quartz
Silicon Dioxide (SiO2)
Quartz crystal cluster in matrix
Silicon dioxide (SiO2)
Alabaster
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Limonite (Iron Ore)
FeO(OH)·nH2O
Black Sand (Magnetite Sand)
Magnetite (Fe3O4)
Chrysocolla-bearing copper mineral specimen (probable turquoise/chrysocolla mix)
Chrysocolla, Cu₂H₂Si₂O₅(OH)₄·nH₂O, with possible turquoise CuAl₆(PO₄)₄(OH)₈·4H₂O and copper oxides
Sandstone with Iron Concretion
Arenite with Limonite/Goethite Concretion
Fossilized Shark Tooth
Chondrichthyes (class)
Fossilized Shark Tooth (Megalodon or Carcharocles species fragment)
Otodus megalodon / Carcharocles spp. (Apatite / Calcium Phosphate)
Silver Nuggets (Natural or Cast)
Native Silver (Ag)
Quartz Geode
Silicon Dioxide (SiO2) in Geodic Cavity
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Cobaltian Calcite
Cobalt-bearing Calcite (Ca,Co)CO3
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Granite Pebble
Granite
Red Granite Pebble
Intrusive Felsic Igneous Rock (Granite)