Scoria
Image: “Jonathan Zander (<a href="//commons.wikimedia.org/wiki/User:Digon3" title="User:Digon3">Digon3</a>)" (CC BY-SA 3.0)
Mineral NameScoria
Chemical FormulaPrimarily mafic silicates (e.g., pyroxene, olivine, plagioclase feldspar) with high iron and magnesium content.
Crystal Systemamorphous
Lusterdull
Streak Colorgray to brownish-black
Cleavagenone
Fractureirregular
Specific Gravity0.8
Colorsdark gray, black, reddish-brown
Transparencyopaque
Type LocalityWorldwide in volcanic regions
Mineral GroupExtrusive igneous rock
Useslightweight aggregate, landscaping, gas grill briquettes, road construction
Associated Mineralsplagioclase, pyroxene, olivine
Raritycommon
Description
A dark gray, highly vesicular volcanic rock, characterized by numerous small, interconnected gas bubbles, giving it a sponge-like texture.
Geological Context
Scoria forms during explosive volcanic eruptions when mafic lava cools rapidly, trapping volcanic gases that create its characteristic porous texture.
