Basalt
Basalt (Mafic volcanic rock)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic volcanic rock)
Basalt
Basalt
Basalt (Vesicular)
Basalt (Extrusive Mafic Igneous Rock)
River Pebble (Basalt)
Basalt (Aphanitic Mafic Igneous Rock)
Chert (specifically Jasper/Flint)
Chert (SiO2)
Vesicular Basalt (Amygdaloidal)
Amygdaloidal Basalt (Mafic volcanic rock)
Pumice
Pumice (Amorphous volcanic glass)
Pumice
Pumice (a highly vesicular volcanic glass)
Scoria (Vesicular Basalt)
Vesicular Basalt
Sandstone
Arenite
River Pebble (Gneiss or Quartzite variant)
Course-grained Metamorphic Rock (likely SiO2 dominant)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Pumice
Pumice (a highly vesicular amorphous silicate glass)
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Basalt
Mafic igneous rock (primarily Plagioclase feldspar and Pyroxene)
Jasper (specifically Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (specifically Jasper or Flint)
Cryptocrystalline Quartz (SiO2)
Chert (specifically Gray Chert)
Silicon Dioxide (SiO2)
Basalt
Basalt (dominated by plagioclase feldspar and pyroxene minerals)
Amber
Succinite (specifically for Baltic amber; fossilized tree resin)
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Vesicular Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 (Pyroxene) and (Ca,Na)Al(Al,Si)Si2O8 (Plagioclase Feldspar)
Basalt (Vesicular/Amygdaloidal or Water-Worn)
Basalt
Basalt
Basalt (Aphanitic-to-porphyritic mafic volcanic rock)
Basalt (with possible Olivine inclusions)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Basalt (Crushed Stone)
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Extrusive mafic igneous rock
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Basalt (Mafic volcanic rock)
Asphalt Concrete (Bituminous Concrete)
Bituminous aggregate
Pumice
Pumiceous rhyolite / Volcanic glass
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Amber (specifically Cherry Amber)
Succinite (with the chemical formula C10H16O)
Chert (specifically Flint or Common Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Green Opal
Hydrated Silica (SiO2·nH2O)
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
Chert (specifically Tan Chert)
Chert (SiO2)
Jasper (specifically Chert/Ironstone)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)