Opalite
Man-made glass (traditionally simulated Opal)
mineral
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Basalt
Basalt (a mafic extrusive igneous rock)
Igneous
Quartzite Cobble
Quartzite (primarily SiO2)
metamorphic
Ferruginous Sandstone (Ironstone)
Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))
sedimentary
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Ferruginous Sandstone (with Iron Oxide staining)
Clastic Sedimentary Rock - Quartz Arenite/Wacke
sedimentary
Limonitic Quartzite
Metamorphosed sandstone with Limonite (FeO(OH)·nH2O) staining
metamorphic
River Pebble Gravel
Hydrothermally modified Clastic Sediment (mainly Quartzite and Chert)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Sandstone (Greywacke)
Arenite / Clastic Sedimentary Rock
sedimentary
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Green Quartz (Prasiolite/Adventurine/Jasper)
Silicon Dioxide (SiO2)
mineral
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Anthropogenic Material (Man-made Rock)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Granodiorite (Gneissic Pebble)
Granodiorite displaying minor foliation
igneous/metamorphic
Quartz (Citrine or Smoky variant)
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)
sedimentary
Chrysocolla
Hydrated copper phyllosilicate, Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
mineral
Red Jasper
Silicon Dioxide with Iron Oxide impurities (SiO2 + Fe2O3)
Mineral (variety of Chalcedony/Quartz)
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
sedimentary and igneous (mixed)
Blue Aragonite
Aragonite (Calcium Carbonate, CaCO3)
mineral
Greenschist
Greenschist (chlorite-epidote schist)
metamorphic
Sandstone (Ferruginous)
Arenite with Iron-oxide inclusions (SiO2 primarily)
sedimentary
Basalt (Crushed Stone Aggregate)
Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Jasper
Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)
sedimentary
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Man-made Material / Glass
Chert (potentially Flint or Mudstone)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Basalt with Quartz/Feldspar Vein
Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic silicate with secondary mineral inclusions)
Igneous
Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Granite
Granite
igneous
Chrysocolla in Quartz (Quantum Quattro variant)
Hydrated copper silicates (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) often mixed with SiO2
mineral
Chert (variant of Flint)
Chert (SiO2)
Sedimentary
Vesicular Basalt
Mafic Volcanic Rock (Basalt)
igneous
Schist
Mica Schist
metamorphic
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2) with iron and other impurities
sedimentary
Quartzite
Quartzite (primarily composed of SiO O₂)
Sedimentary Rock