extrusive
Andesite
Andesite is a fine-grained, gray to greenish-gray extrusive igneous rock found in volcanic regions worldwide.
Hardness 6–7Andes Mountains
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extrusive
Basalt
Basalt is a dark, fine-grained extrusive igneous rock formed from rapidly cooled lava flows.
Hardness 5–6India (Deccan Traps)
extrusive
Obsidian
Obsidian is a natural volcanic glass formed when lava cools rapidly, resulting in a smooth, glassy rock often found in dark colors.
Hardness 5–5.5Mexico
extrusive
Pumice
Pumice is a light, porous volcanic rock formed from rapidly cooling lava. It is widely used as an abrasive and in construction.
Hardness 5.5–6Italy
extrusive
Rhyolite
Rhyolite is a light-colored, fine-grained extrusive igneous rock, chemically similar to granite.
Hardness 6–7USA
extrusive
Scoria
Scoria is a dark, porous volcanic rock formed from basaltic magma, notable for its vesicular texture and lightweight nature.
Italy