Basalt Porphyry
Porphyritic Basalt
igneous
Category
Mineral, Specifically A Rock Fragment
Browse mineral, specifically a rock fragment specimens identified by the Rock Identifier community.
Chert (Iron-stained)
Chert (Silicon Dioxide, SiO2)
sedimentary
Agate (Geode nodule fragment)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
sedimentary
Chert (Arrowhead Preform)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Citrine
Crystalline Quartz (SiO2) with iron impurities
mineral
Quartz (specifically Milky/Gray Quartz)
Silicon Dioxide (SiO2)
mineral
Banded Iron Formation (BIF) with Quartz
Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)
Sedimentary
River Rocks (Black)
Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts
Sedimentary
Granite (Alkali-feldspar Granite)
Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)
igneous
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8)
mineral
Green Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Mineral
Ooids (Oolites)
Ooids (composed of Calcium Carbonate / CaCO3)
sedimentary
Quartz pebble (Quartztite fragment)
Silicon Dioxide (SiO2)
mineral
Moonstone (Feldspar)
Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8)
mineral
Chert (or Flint)
Chert (cryptocrystalline quartz), SiO2
Sedimentary
Amber
Succinite (specifically for Baltic amber); Complex mixture of organic compounds (C10H16O)
Organic Mineraloid
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
sedimentary
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Sandstone Beach Pebble
Clastic Sandstone (SiO2 - Quartz-dominant)
sedimentary
Chert (Flint)
Microcrystalline quartz (SiO2)
sedimentary
Red Sandstone
Arenite (with Iron Oxide cement)
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2 with minor Fe2O3)
sedimentary
Basalt (Vesicular)
Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)(Si, Al)2O6 with (Ca, Na)(Al, Si)4O8
igneous
Milky Quartz (Tumble Fragment)
Silicon Dioxide (SiO2)
mineral
Iron-Nickel Meteorite fragment
Siderite (meteoritic iron), composed primarily of Kamacite (α-(Fe,Ni)) and Taenite (γ-(Fe,Ni))
mineral
Conglomerate
Clastic sedimentary rock (Polymictic Conglomerate)
sedimentary
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
metamorphic
Jasper (specifically Bloodstone or Heliotrope variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary (chemically precipitated)
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Ocean Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
mineral
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (specifically Flint or Jasper-Chert)
Silicon Dioxide (SiO2)
sedimentary
Limestone (specifically Dolomitic Limestone)
Calcium Magnesium Carbonate (CaMg(CO3)2)
sedimentary
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
sedimentary