Crushed Limestone
Calcium Carbonate (CaCO3)
Category
Browse sedimentary like (industrial composite) specimens identified by the Rock Identifier community.
Crushed Limestone
Calcium Carbonate (CaCO3)
Diamond
Native Carbon (C)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Black Diamond (Carbonado)
Carbonado (Polycrystalline Diamond)
Mica Schist
Schist (muscovite-biotite schist)
Orange Calcite
Calcium Carbonate (CaCO3)
Citrine Quartz
Crystalline Quartz (SiO2 with iron impurities)
Quartzite
Quartzite (SiO2)
Quartzite (River Stone)
Quartzite (SiO2)
Calcite (Yellow/Orange variety - sometimes called Honey Calcite)
Calcite
Pumice
Vesicular volcanic glass (primarily SiO2)
Diabase (Dolerite) Cobble
Diabase / Dolerite
Feldspar (Granite Pegmatite matrix)
Potassium Feldspar (KAlSi3O8) / Quartz Mixture
Small pale mineral fragment
Unidentified; possibly quartz, calcite, or feldspar
Vesicular Basalt with Oxidized Crust
Vesicular Basalt (Iron-rich extrusive volcanic rock)
Anthracite Coal
Anthracite (Carbon C)
Siltstone / Slate
Siltstone / Low-grade Slate
Banded Agate
Agate (Cryptocrystalline Quartz, SiO2)
Slag
Ferrous slag (by-product of iron smelting)
Milky Quartz
Silicon Dioxide (SiO2)
Agate
Agate (Silicon Dioxide, SiO2)
Marble
Metamorphosed Limestone (principally CaCO3)
Marble
Metamorphosed Limestone (calcite formulation CaCO3)
Hypersthene
(Mg,Fe)SiO3 - Enstatite-Ferrosilite series
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)
Yellow Sapphire (Raw)
Corundum (Al2O3)
Basalt
Basalt (Mafic volcanic rock)
Ruby in Matrix
Corundum (Al2O3)
Rough Ruby
Corundum (Al2O3 with Chromium impurities)
Quartz Pebble (Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Greenschist / Chloritaform Schist
Chlorite Schist (Group of Silicate Minerals)
Pumice
Pumice (Highly vesicular felsic volcanic rock)
Likely anthracite coal
Anthracite; predominantly carbon (C), with minor mineral impurities
Agate
Silicon Dioxide (Chalcedony), SiO2
Agate
Silicon dioxide (Chalcedony), SiO2
Limestone
Calcium Carbonate (CaCO3)
Jasper / Yellow Chalcedony Pebble
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Chert (Flint)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Banded Calcite (often sold as 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Limestone
Calcium Carbonate (CaCO3)