Basalt
Basalt
Category
Browse igneous or sedimentary specimens identified by the Rock Identifier community.
Basalt
Basalt
Basaltic Scoria
Scoria (Vesicular Basalt/Andesite)
Scoria (Basaltic)
Vesicular Basalt
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Obsidian (Apache Tear)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Granite (with Beryl/Aquamarine)
Granite (Feldspar, Quartz, Mica, and Beryl Be3Al2Si6O18)
Basalt
Basalt (Mafic volcanic rock)
Pumice
Pumicite (Amorphous Volcanic Glass)
Pink Granite
Granite (Felsic Plutonic Rock)
Basalt
Basalt
Gossan (Iron Hat)
Limonitic Gossan (Fe-oxide/hydroxide complex)
Granite
Granite (composed primarily of Quartz SiO2, Orthoclase KAlSi3O8, and Plagioclase NaAlSi3O8 to CaAl2Si2O8)
Granite (Weathered)
Grano-diorite / Granite (SiO2 rich intrusive rock)
Andesite
Intermediate Volcanic Rock (Andesite)
Red Scoria (Lava Rock)
Vesicular Basalt / Scoria
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
River Pebble (Gabbro or Dark Sandstone variety)
Mafic Intrusive Rock (Plagioclase Feldspar and Pyroxene)
Granite
Granite (Main minerals: Quartz SiO2, Feldspar KAlSi3O8, Mica)
Pegmatite
Granitic Pegmatite
Basalt with Porphyritic Texture
Porphyritic Basalt
Gabbro
Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)
Porphyritic Rhyolite (Cookie Stone)
Porphyritic Rhyolite (SiO2, with phenocrysts)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Diorite
Diorite
Granite
Granite (Silicic Plutonic Rock)
Basalt with Quartz Veins
Basalt (SiO2 range 45-52%)
Diorite
Phaneritic intermediate plutonic rock
Basalt (River Pebble)
Mafic volcanic rock (primarily Plagioclase feldspar and Pyroxene)
Scoria (often called Lava Rock)
Vesicular Basalt / Scoria
Basalt (Vesicular and Ropey)
Vesicular Basalt / Pahoehoe Basalt
Pumice or Scoria
Vesicular volcanic rock
Basalt with Vesicles
Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)
Black Tourmaline in Quartz
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) in Silicon Dioxide (SiO2)
Basalt (River Stone)
Mafic volcanic rock
Basalt
Basalt (comprising Plagioclase feldspar, Pyroxene, and Olivine)
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)
Basalt (River Stone)
Basalt
Diabase (Greenstone Pebble)
Diabase or Dolerite
Granite
Granite (composed of Quartz, Feldspar, and Mica/Amphibole)
Basalt
Mafic Volcanic Rock
Obsidian
Obsidian (Volcanic Glass, SiO2)
River Rock (Basalt)
Basalt (SiO2 range: 45-52%)