Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Metamorphic, likely Sedimentary with Quartz veins
Category
Sedimentary (Volcanic)
Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.
Ocean Jasper
Silicon Dioxide (SiO2) with various inclusions
igneous/sedimentary mixed (Orbicular Jasper)
Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
igneous
Porphyritic Basalt (Peanut Obsidian/Star Galaxy-style)
Porphyritic Basalt (Silica-rich Volcanic Rock)
igneous
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
igneous
Botryoidal Chalcedony
Chalcedony (SiO2)
Mineral
Agate (Chalcedony)
Agate (Silicon Dioxide - SiO2)
mineral
Banded Agate
Silicon dioxide (SiO2) - variety of Chalcedony
mineral
Pumice
Pumice (Vesicular Rhyolite/Andesite)
igneous
Amethyst
Amethyst (variety of Quartz, SiO2)
mineral
Jasper (Green/Yellow Moss Jasper)
Silicon Dioxide (SiO2)
mineral
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
mineral
Basalt (River Rock/Cobble)
Basalt (no specific mineral formula as it's a rock)
Igneous
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
mineral
Basalt (River Cobble)
Basalt (Mafic volcanic rock)
igneous
Pumice
Pumice (a highly vesicular, silicic volcanic rock)
igneous
Basalt
Basalt (Mafic Extrusive)
igneous
Stilbite
Stilbite-Ca (Hydrated calcium sodium aluminum silicate), NaCa4(Si27Al9)O72·28H2O
mineral
Pumice
Vesicular Rhyolite / Pumice
igneous
Jasper
Silicon Dioxide (SiO2)
Mineral
Basalt
Extrusive mafic igneous rock
igneous
Snowflake Obsidian
Obsidian with Cristobalite inclusions (70–75% SiO2)
igneous
Basalt River Pebble
Mafic Igneous Rock (Fine-grained Basalt)
igneous
Basalt Porphyry
Porphyritic Basalt
igneous
Basalt
Extrusive mafic igneous rock
igneous
Pumice
Highly vesicular volcanic glass (unnamed scientific variant: Rhyolitic/Andesitic Pumice)
igneous
Fire Opal (Common/Precious in Matrix)
Hydrated Silica (SiO2·nH2O)
mineral
Lapis Lazuli (blue bead) and Moss Agate (green heart)
Lapis Lazuli (lazurite-based rock) and Moss Agate (SiO2 with manganese/iron inclusions)
metamorphic (Lapis) and sedimentary/igneous assoc. (Moss Agate)
Pumice
Pumice (Highly vesicular felsic extrusive igneous rock; primarily SiO2)
igneous
Peridot
Olivine ((Mg,Fe)2SiO4)
Mineral
Larimar
Pectolite (a variety of pectolite, NaCa2Si3O8(OH))
Mineral
Druzy Agate (Star-cut Geode Slice)
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline Quartz
mineral
Black Onyx
Silicon dioxide (SiO2) with parallel banded structure
Mineral (variety of chalcedony)
Carnelian Agate
Chalcedony (SiO2) with iron oxide inclusions
mineral
Peridot (Olivine)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
mineral
Ethiopian Opal (Welo Opal)
Hydrated Amorphous Silica (SiO2·nH2O)
mineraloid
Basaltic Scoria
Scoria (Vesicular Basalt/Andesite)
igneous
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
mineral
Agate (specifically Botswana or Banded Agate variety)
Chalcedony (Silicon Dioxide, SiO2)
mineral
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Mineral
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary