Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Category
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Basalt
Basalt (Aphanitic-to-porphyritic mafic volcanic rock)
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Azurite in Matrix
Azurite (Cu3(CO3)2(OH)2)
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
Satin Spar (Gypsum)
Hydrous Calcium Sulfate (CaSO4·2H2O)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Marble
Recrystallized Calcite (CaCO3)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Basalt
Basalt (composition predominately plagioclase feldspar and pyroxene)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Conglomerate with Quartz Inclusions
Conglomerate (clastic sedimentary rock) with internal Quartz (SiO2)
Basalt
Extrusive mafic igneous rock
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Gold Flakes
Native Gold (Au)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Jasper or Chalcedony
Microcrystalline Quartz (SiO2)
Flint (Chert)
Silicon Dioxide (SiO2)
Chrysocolla
Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O
Rough Emerald
Emerald (Beryl), Be3Al2(SiO3)6
Quartz
Silicon Dioxide (SiO2)
Scoria (Red Lava Rock)
Scoria
Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)
Basalt with Hematite staining
Extrusive mafic igneous rock with Fe2O3
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz (Drusy/Crystalline)
Silicon Dioxide (SiO2)
Orange Calcite point
Calcite (Calcium Carbonate, CaCO3)
Rutilated Quartz
Silicon Dioxide (SiO2) with inclusions of Titanium Dioxide (TiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
Olivine
Magnesium Iron Silicate ((Mg, Fe)₂SiO₄)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Pyrite and Sunstone
Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)
Gastropod Internal Mold (Steinkern)
Class Gastropoda fossil mold (Phylum Mollusca)
Sandstone Concretion
Sandstone (Sedimentary Rock) with silica or calcite cement
Native Gold (in Jewelry)
Gold (Au)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)