Porphyry (specifically Porphyritic Basalt or Andesite)
Porphyritic extrusive igneous rock (Mg,Fe)2SiO4 (Olivine inclusions/Plagioclase Feldspar)
igneous
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Dendritic Agate
Dendritic Agate (Silicon Dioxide with Manganese or Iron Oxide inclusions, SiO2)
mineral
Banded Agate Geode
Silicon Dioxide (SiO2)
mineral
Andesite Porphyry
Andesite (extrusive volcanic rock)
igneous
Quartz Geode (Druzy)
Crystalline Silicon Dioxide (SiO2)
mineral
Quartz Geode (Cracked)
Silicon Dioxide (SiO2)
mineral
Arsenic (Native)
Arsenic (As)
mineral
Gastly (Trick or Trade Halloween Series)
Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)
Mineral (Synthetic - Paper and Ink Polymorph)
Native Sulfur
Sulfur (S8)
mineral
Gold Nugget
Native Gold (Au)
mineral
Amygdaloidal Basalt with Agate/Chalcedony Infills
Amygdaloidal Basalt (Composition: SiO2 and (Mg,Fe)2SiO4 in matrix; SiO2 in amygdule)
igneous
Grey Chalcedony (Tumbled Moon)
Microcrystalline Quartz (SiO2)
mineral
Schist
Mica Schist (Medium-grade metamorphic rock)
metamorphic
Gold Nugget
Native Gold (Au)
mineral
![Limonitic Scoria (Vesicular Basalt with Iron Staining) (Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]) — igneous](https://media.rockidentification.com/2f0eaf7f-d274-4028-af3e-e31436d83d19-thumbnail.jpg)
Limonitic Scoria (Vesicular Basalt with Iron Staining)
Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]
igneous
Garnet-bearing Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone
Arenite
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Red Jasper (River Pebble)
Silicon Dioxide (SiO2) with hematite impurities
sedimentary (microcrystalline quartz)
Emerald in Matrix
Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
sedimentary
Agate (Slab)
Agate (Cryptocrystalline variety of Quartz, SiO2)
Mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
sedimentary
Chondrite Meteorite
Ordinary Chondrite (Fe-Ni alloy, Olivine, Pyroxene)
Mineral
Quartzite Pebble (River Rock)
Quartzite (primarily SiO2)
metamorphic
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
sedimentary
Quartzite
Quartzite (Primary mineral: SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
mineral
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Black Onyx
Silicon Dioxide (SiO2) with cryptocrystalline structure
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Blue Quartzite
Quartzite (primarily SiO2 with inclusions like Dumortierite or Magnesio-riebeckite)
metamorphic
Bismuth Crystal
Bismuth (Bi)
mineral
Blue Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2)
mineral
Quartzite
Quartzite (Primary mineral: Quartz, SiO2)
metamorphic
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
metamorphic
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Quartzite
Quartzite (SiO2)
metamorphic