Basalt with vesicles/amygdules
Basalt (containing volcanic glass and plagioclase)
igneous
Category
Sedimentary (Volcanic)
Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
igneous
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Pumice
Pumice (a highly vesicular volcanic glass)
igneous
Basalt Porphyry
Porphyritic Basalt
igneous
Fossilized Fish (Lepidotes)
Lepidotes sp. (Order: Lepisosteiformes)
sedimentary
Tektite (Indochinite)
Tektite (High-silica natural glass)
igneous
Lake Superior Agate
Cryptocrystalline Quartz (SiO2)
mineral
Red Rhyolite Porphyry
Rhyolite (Porphyritic texture)
igneous
Basalt with Olivine Phenocrysts
Porphyritic Basalt (containing Mg2SiO4 - Fe2SiO4)
igneous
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
igneous
Chalk / Sedimentary Limestone
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
sedimentary
Chalk (Sedimentary Limestone)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Fossilized Bivalve Shell
Bivalvia (fossil specimen)
sedimentary
Concretion (Sandstone)
Sandstone Concretion
sedimentary
Weathered Volcanic Rock (possibly Rhyolite or Andesite Pebble)
Volcanic rock (e.g., Rhyolite or Andesite, specific identification would require thin section analysis or chemical assay). Mineral composition: Primarily feldspars (orthoclase and/or plagioclase), quartz (in rhyolite), micas, amphiboles, and sometimes pyroxenes.
Igneous, specifically volcanic/extrusive (possibly Rhyolite or Andesite)
Dalmatian Jasper
Peralkaline rhyolite with Arfvedsonite inclusions
igneous
Granodiorite
Phaneritic Plutonic Granodiorite
igneous
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2) with inclusions of Hematite or Chlorite
mineral
Moss Agate Geode Sphere
Silicon Dioxide (SiO2) - Chalcedony with Chlorite or Manganese inclusions
mineral
Blue Lace Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Onyx (Black Onyx)
Silicon Dioxide (SiO2) - Chalcedony variety
Mineral
Mother of Pearl and Onyx
Aragonite (Mother of Pearl) and Chalcedony (Onyx)
mineral
Botryoidal Hematite (Kidney Ore)
Iron(III) oxide (Fe2O3)
Mineral
Carnelian
SiO2 (Silicon Dioxide) - Carnelian Agate/Chalcedony
mineral
Diorite
Diorite
igneous
Diorite
Intermediate plutonic igneous rock
Igneous
Blue Chalcedony (Blue Lace Agate variety)
Silicon Dioxide (SiO₂)
mineral
Banded Agate
Chalcedony / Silicon Dioxide (SiO2)
mineral
Banded Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
Mineral
Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity isotopes)
igneous
Apache Tear
Obsidian (Hydrated Volcanic Glass, SiO2)
igneous
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
igneous
Porphyritic Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
igneous
Red Jasper
Silicon Dioxide (SiO₂)
Sedimentary Rock (Cryptocrystalline Quartz)
Blue Lace Agate
Cryptocrystalline Quartz (SiO2)
mineral
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Scoria (Red Lava Rock)
Scoria
igneous