Lava Rock (Scoria)
Extrusive basaltic scoria
igneous
Category
Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic volcanic rock)
igneous
Quartz-veined Basalt
Amygdaloidal or Porphyritic Basalt with Silicon Dioxide (SiO2) vein
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)
SiO₂ (silicon dioxide)
Sedimentary
Basalt
Basalt
igneous
Quartz
Quartz (Silicon Dioxide - SiO2)
Mineral
Ferruginous Slag (Iron Smelting Byproduct)
Fused Silicate Scoria (Amorphous mixture of FeO, SiO2, and CaO)
Antropogenic Glass / Mineraloid
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Black Jasper
Silicon Dioxide (SiO2) with inclusions
sedimentary
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with impurities
sedimentary or igneous-associated mineral
Jasper (specifically Bloodstone or Heliotrope variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Sedimentary / Mineral
Quartz (specifically Clear Quartz with iron/hematite staining)
Silicon Dioxide (SiO2)
mineral
Banded Agate (specifically Carnelian Agate color)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Pumice
Pumice (Vesicular volcanic glass / Rhyolite or Trachyte)
igneous
Quartz
Quartz (SiO₂)
Mineral
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
igneous
Schist (specifically Mica Schist)
Mica Schist (primarily composed of Muscovite KAl2(AlSi3O10)(OH)2 and Biotite)
metamorphic
Sandstone
Arenite (primarily SiO2)
sedimentary
Amber
Succinite (specifically for Baltic Amber), Formula: C10H16O
Organic Gemstone (often associated with Sedimentary sequences)
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Basalt
Basalt (composition of plagioclase feldspar, pyroxene, and olivine)
igneous
Basalt (River Pebble)
Extrusive mafic igneous rock
igneous
Quartz (specifically Clear Quartz or Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Agate (specifically a small Chalcedony nodule)
Agate (Cryptocrystalline variety of Quartz, SiO2)
mineral
Gneiss (specifically a water-worn pebble)
Gneiss
metamorphic
Pumice
Pumice (a highly vesicular volcanic rock)
igneous
Scoria (Lava Rock)
Vesicular Basalt / Scoria
igneous
Pumice
Pumice (a highly vesicular volcanic glass)
igneous
Pumice
Pumice (Vesicular volcanic glass)
igneous
Amethyst and Limestone
Amethyst (SiO2 - Silicon Dioxide) and Limestone (CaCO3 - Calcium Carbonate)
The purple specimen is a mineral (Amethyst); the white specimen is a sedimentary rock (Limestone or Marble).
Pumice
Pumice (a highly vesicular volcanic rock)
igneous
Vesicular Rhyolite
Extrusive igneous rock (high-silica rhyolite)
igneous
Basalt
Mafic Igneous Rock
igneous
Basalt
Mafic Igneous Rock
igneous
Leopard Skin Jasper
Chalcedony (cryptocrystalline Quartz)
Mineral
Gneiss (specifically Banded Gneiss)
Gneiss
metamorphic
Basalt with Calcite Veins
Aphanitic mafic volcanic rock with CaCO3 inclusions
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Basalt
Basalt (primarily composed of Plagioclase Feldspar and Pyroxene)
igneous