Porphyry
Porphyritic Rock
igneous
Category
Industrial Byproduct (Anthropogenic Rock)
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Conglomerate
Conglomerate rock
sedimentary
Porphyritic Basalt
Porphyritic Basalt
igneous
Dark gray rounded stone, possibly basalt or slag
Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or iron-rich industrial slag
igneous
Rounded granite or granitic gneiss cobble
Granite; primarily quartz, feldspar, and mica (exact identification requires a fresh surface and testing)
igneous
Rounded sandstone pebble
Quartz-rich sandstone (likely arkosic or lithic sandstone)
sedimentary
Vein Quartz in Basalt or Mafic Rock
Silicon Dioxide (Quartz veins in volcanic host rock)
igneous
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)
Granite and Igneous Rock Collection
Intrusive igneous rock / Granitoid
igneous
Shale
Argillaceous Rock
sedimentary
Sandstone and Conglomerate pebbles
Sedimentary clastic rock
sedimentary
Conglomerate
Conglomerate rock
sedimentary
Dalmatian Stone
Dalmatian Jasper (Aplite rock composition)
igneous
Sandstone (Wonderstone)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sedimentary Rock Fragments
Clastic Sedimentary Rock
sedimentary
Basalt
Mafic extrusive igneous rock
igneous
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Basalt with Amygdales
Amygdaloidal Basalt
igneous
Quartz Geode
Silicon Dioxide (SiO2) within a sedimentary or igneous host
sedimentary
Basalt with Quartz Veining
Veined Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine with quartz/calcite infill)
igneous
Basalt with Quartz/Calcite Veins
Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)
igneous
Quartzite River Pebble
Quartzite (primarily Silicon Dioxide, SiO2)
metamorphic
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Porphyritic Basalt (Drill Core)
Porphyritic Basalt with Plagioclase Phenocrysts
igneous
Ferruginous Sandstone (Ironstone)
Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))
sedimentary
Schist
Mica Schist (contains muscovite/biotite and quartz)
metamorphic
Pink Dyed Agate (Banded Chalcedony)
Silicon dioxide (SiO2) - variety Chalcedony
mineral
Polished blue-green glassy slag or coated mineral fragment
Most likely man-made colored glass/slag; exact composition cannot be determined visually
mineral
Grey River Pebble (Greywacke / Basalt)
Stream-rounded silicate rock pebble
sedimentary
Chalk
CaCO3 (Calcium Carbonate)
sedimentary
Graphite
Graphite (Carbon, C)
mineral
Bentonite Clay
Al2O3·4SiO2·H2O (Hydrous aluminum silicate)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Greywacke
Greywacke (Lithofeldspathic Sandstone)
sedimentary
Quartzite
Quartzite (primarily Silicon Dioxide, SiO2)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Glauconite (Sandstone or Shale)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Black Sand (Magnetite Sand)
Magnetite (Fe3O4)
mineral
Quartz (Common Grains)
Silicon Dioxide (SiO2)
mineral
Chert (Gravel pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz Geode
Crystalline Quartz (SiO2) within a sedimentary/igneous host
mineral