volcanic glass
Cooled molten rock
Volcanic glass is rock formed when lava cools so rapidly that crystals don't have time to develop, resulting in a smooth, glassy texture.
Obsidian is the most familiar example—black, shiny, and sharp enough that ancient peoples fashioned it into blades and arrowheads.
The archaeologists found volcanic glass tools at the site.
Glassy igneous rock
- basaltFine-grained volcanic stone
- rhyolitePale volcanic igneous rock
- pumiceLightweight volcanic abrasive
- scoriaPorous volcanic ejecta
tuff · lava · magma · silica · pyroclastic · andesite · perlite · tephra
Glassy igneous rock
- bladeFlat cutting edge
- scraperTool for removing buildup
- arrowheadPiercing end of projectile
- spearpointSharpened projectile tip
knapping · flaking · core · lithic · microblade · tool · prehistoric · artifact
obsidian
Glassy igneous rock
- basaltFine-grained volcanic stone
- rhyolitePale volcanic igneous rock
- pumiceLightweight volcanic abrasive
scoria · tuff · lava · magma · silica · pyroclastic · andesite · perlite · tephra · extrusive
obsidian
Glassy igneous rock
spearpoint · knapping · flaking · core · lithic · microblade · tool · prehistoric · artifact · archaeology
conchoidal
Curved fracture surface shape
brittle · amorphous · smooth · lustrous · opaque · translucent · sheen · reflective · sharp · edge
jewelry
Ornamental personal accessories
bead · amulet · sculpture · ornamental · polished · collectible · lapidary · gemstone · tumbled
- volcanoesMount Fuji, caldera, lava, crater, Etna
- volcaniclava, magma, tephra, pumice, scoria
- Volcanismmagma, eruption, lava flow, magma chamber, lava dome
- Hawaiian VolcanoesKilauea, Mauna Loa, Haleakala, volcanoes, lava
- volcanic geologylava, magma, crater, caldera, calderas
- volcanic rocksbasalt, rhyolite, andesite, pumice, obsidian
volcanic glassgranite
Igneous rock, quartz-rich
crystal · quartz crystal · feldspar · quartz · basalt
volcanic glasslimestone
Carbonate sedimentary rock
sandstone · shale · metamorphic rock · chalk · sedimentary rock
glass, volcano, volcanic, volcanism, volcanology, volcanically, volcanologist