Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Basalt (Vesicular)
Extrusive Mafic Igneous Rock
Blue Chalcedony
Chalcedony (cryptocrystalline Silicon Dioxide - SiO2)
Asphalt (Bituminous Slate/Sandstone)
Asphaltum / Bituminous Rock
Basalt with Quartz Veins
Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)
Quartz Vein in Siltstone
SiO2 (Quartz) on clastic sedimentary matrix
Quartzite
Quartzite (primarily SiO2)
Sandstone (Quartzite Pebble)
Arenite (primarily SiO2)
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Chrysocolla on Quartz with Iron Oxides
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
Alexandrite in Matrix
Chrysoberyl (BeAl2O4 with Chromium impurities)
Basalt River Stone (Tumbled)
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Basalt (composition of Plagioclase feldspar, Pyroxene, and Olivine)
Jasper (Green Jasper / Chert)
Silicon Dioxide (SiO2) with iron/clay inclusions
Granite Pebble
Igneous Intrusive Rock (Quartz-Feldspar-Mica Phenocrysts)
Basalt Pebble
Extrusive mafic igneous rock
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
Basalt with Limonite stains
Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)
Iron-Nickel Meteorite
Siderite (Iron Meteorite), primarily Fe-Ni alloy
Serpentine
Serpentinite (group of minerals including Antigorite, Lizardite, or Chrysotile) (Mg, Fe)3Si2O5(OH)4
Red Jasper with Quartz Veining
Jasper (Silicon Dioxide, SiO2) with Quartz (SiO2) inclusions
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
Anthracite Coal
Anthracite
Basalt Pebble
Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)Si2O6 and (Ca, Na)AlSi3O8
Unakite
Epidotized Granite (SiO2 with Ca2(Al, Fe)3(SiO4)3(OH))
Sandstone
Arenite (SiO2 primarily)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Malachite
Copper carbonate hydroxide Cu2CO3(OH)2
Basalt
Basalt (Mafic Extrusive)
Quartzite with Quartz Veining
Quartzite (primarily SiO2)
Basalt
Vesicular Basalt
Sandstone
Arenite (primarily SiO2)
Basalt with Iron Oxidation
Extrusive Mafic Igneous Rock (composed of Plagioclase and Pyroxene)
Sandstone
Arenite
Basalt
Basalt (Mafic Aphanitic Igneous Rock)
Dacite
Dacite (Intermediate volcanic rock)
Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8
Sandstone (Iron-stained)
Clastic sedimentary rock (SiO2 with Fe2O3 staining)
Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
Peridot
Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4