Vesicular basalt (weathered volcanic rock)
Basalt, chiefly plagioclase feldspar, clinopyroxene, and possibly olivine/iron oxides
igneous
Category
Not A Rock (Synthetic Material)
Browse not a rock (synthetic material) specimens identified by the Rock Identifier community.
Learn about Not A Rock (Synthetic Material) in the encyclopedia
View all →
Blue Lace Agate
Cryptocrystalline Quartz (SiO2) with trace minerals
sedimentary
Chert (and its variety Flint)
Silicon dioxide (SiO2) / Microcrystalline quartz
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (specifically Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone
Sandstone (various mineral compositions)
Sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Iron-stained Quartz Vein
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Fossilized Bone Fragment
Vertebrate Fossil Material (Apatite/Calcium Phosphate)
fossil
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Limestone
Sedimentary carbonate rock (CaCO3)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Granite (Polished Slab)
Granite (Plutonic Igneous Rock)
igneous
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Basalt
Aphanitic Mafic Igneous Rock
igneous
Diorite
Diorite (an intrusive igneous rock)
igneous
Schist
Crystalline Metamorphic Rock (Schistose)
metamorphic
Amethyst-bearing quartz cluster
Quartz, SiO₂; purple coloration from irradiation and trace iron
mineral
Quartz pebble in concrete
Quartz (SiO₂), embedded in Portland-cement concrete
mineral
Coprolite
Fossilized Feces
fossil
Granitic Quartz with Feldspar
Granite (composed primarily of SiO2 and KAlSi3O8)
igneous
Thunderegg (Agetized Geode nodule)
Rhyolitic Agate Nodule (SiO2 filling volcanic cavities)
igneous
Brecciated jasper, possibly rainforest jasper or brecciated rhyolite
Brecciated microcrystalline quartz (SiO₂), commonly called jasper; the green portions may contain epidote, chlorite, or iron-bearing silicates, while red-brown areas are typically hematite or other iron oxides
sedimentary
Likely weathered river pebble
Indeterminate lithology; possibly fine-grained sandstone, siltstone, or chert
sedimentary
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Weathered porphyritic volcanic rock
Likely altered andesite or rhyolite porphyry
igneous
Coquina
Biogenic Limestone (Calcitic)
sedimentary
Pink Granite
Granite (Felsic intrusive igneous rock)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Porphyritic granite or granodiorite
Coarse-grained plutonic rock composed mainly of quartz (SiO₂), feldspar, and mica/amphibole
igneous
Unidentifiable Rock Fragment
Uncertain
Piddock bored rock (likely Mudstone or Shale)
Ichnofossil (Gastrochaenolites borings) in Fine-grained Sedimentary Rock
sedimentary
Epidotite (Unakite-related Epidote)
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
metamorphic
Porous quartz-rich rock, likely weathered rhyolite or silicified volcanic breccia
Rhyolite or volcanic breccia; predominantly microcrystalline quartz (SiO₂) with altered feldspar and iron oxides
igneous
Gneiss (Gneissic Granite Pebble)
Metamorphic rock rich in Quartz, Feldspar, and Mica
metamorphic
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil