Echinoid Fossil (Sea Urchin Fossil)
Echinoidea
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Echinoid Fossil (Sea Urchin Fossil)
Echinoidea
Gneiss
Gneiss
Pegmatite (Granitic)
Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)
Erythrite on Matrix
Cobalt Bloom (Co3(AsO4)2·8H2O)
Limonite
Limonite (Hydrous iron oxides, predominantly Goethite FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Silver Nuggets (Natural or Cast)
Native Silver (Ag)
Granite with Epidote
Granite, containing quartz, feldspar, and epidote
Pegmatite
Igneous Pegmatite
Obsidian
Volcanic Glass (SiO2)
Pegmatite (Granitic)
Granitic Pegmatite
Rainbow Fluorite
Calcium Fluoride (CaF2)
Epidosite (Epidote-Quartz rock)
Epidote-rich hydrothermal rock
Granitic Pegmatite
Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8, Mica: KAl2(AlSi3O10)(OH)2)
Sandstone
Arenite
Rose Quartz
Silicon Dioxide (SiO2)
Biotite Mica
K(Mg, Fe)3AlSi3O10(F, OH)2
Feldspar (specifically Orthoclase)
Potassium aluminum silicate (KAlSi3O8)
Geode half
Geode (often quartz/chalcedony based)
White Marble
Recrystallized Calcite (CaCO3)
Sandstone
Arenite (composed primarily of SiO2)
Aragonite (Botryoidal/Coralloidal variety)
Aragonite (CaCO3)
Sandstone
Sandstone (clastic sedimentary rock, predominantly SiO2)
Fossilized Stingray Mouth Plate
Myliobatidae gen. et sp. indet. (e.g., Myliobatis, Aetobatus)
Greenstone
Protolith: Basaltic rock
Greenstone
Greenschist / Meta-basalt
Raw Corundum (Sapphire/Ruby variant)
Aluminum oxide (Al2O3)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Corundum (variety Ruby/Sapphire)
Aluminum Oxide (Al2O3)
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
Limonite with Quartz
Hydrated Iron Oxide Hydroxide, FeO(OH)·nH₂O with SiO₂
Quartz Geode
Silicon Dioxide (SiO2) in Geodic Cavity
Sandstone
Sandstone (clastic sedimentary rock, predominantly SiO2)
Erythrite in Cobaltite Ore
Erythrite (Co3(AsO4)2·8H2O) with Cobaltite (CoAsS)
Limonite/Goethite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Okenite (in Zeolite matrix)
Okenite (CaSi2O5 · 2H2O)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Concretion (Sandstone)
Sandstone Concretion
Orbicular Granite
Orbicular Granidiorite / Plutonic Igneous Rock
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Botryoidal chalcedony (likely common opal)
Silica, SiO₂; chalcedony is microcrystalline quartz, while opal is hydrated amorphous silica (SiO₂·nH₂O)