Types of Volcanic Rock & Igneous Formation
Types Of Volcanic Rock & Igneous Formation is a structured science dataset with 15 entries. Its fields include Rock Type, Texture, Composition. The source values are preserved as a structured reference table.
Every row is shown below and is also available as CSV, JSON, or Excel.
Dataset details
- Table scope
- All 15 rows
- Fields
- 5 columns
- Source
- Community curated
- Data updated
- Mar 7, 2026
Included fields: Rock Type, Texture, Composition, How It Forms, Known For.
The table contains every record in this dataset; the same records are available in each download format.
Preview observations
- Texture groups
- 11 distinct values
- Across 15 preview rows
Useful for
- Comparing Rock Type, Texture, and Composition across science entries
- Building reference tables, charts, or analyses from 15 downloadable records
Rock Type↕ | Texture↕ | Composition↕ | How It Forms↕ | Known For↕ |
|---|---|---|---|---|
Obsidian | Glassy (no crystals) | Felsic (silica-rich, >70% SiO2) | Rapid cooling of viscous lava, no time for crystals | Natural volcanic glass, razor-sharp edges used for ancient tools, obsidian scalpels sharper than steel, Apache tears |
Pumice | Vesicular (extremely porous) | Felsic to intermediate | Gas-rich explosive eruption, frothy lava solidifies mid-air | Only rock that floats on water, pumice rafts can cover ocean after eruptions, used for exfoliation and concrete |
Basalt | Fine-grained (aphanitic) | Mafic (45-52% SiO2) | Rapid cooling of low-viscosity lava at surface | Most common rock on Earth's surface, forms ocean floor, Giant's Causeway columns, Hawaiian islands are basalt |
Granite | Coarse-grained (phaneritic) | Felsic (quartz, feldspar, mica) | Slow cooling deep underground (plutonic) | Backbone of continents, kitchen countertops, Mount Rushmore carved in granite, extremely durable building stone |
Rhyolite | Fine-grained (aphanitic) | Felsic (same as granite but extrusive) | Rapid cooling of silica-rich lava at surface | Granite's volcanic equivalent, produces most explosive eruptions, Yellowstone caldera erupts rhyolite, flow-banded textures |
Andesite | Fine-grained, sometimes porphyritic | Intermediate (57-63% SiO2) | Eruption at subduction zones (convergent boundaries) | Named after the Andes mountains, dominant rock of volcanic arcs, Krakatoa and Mount Pinatubo erupted andesite |
Gabbro | Coarse-grained (phaneritic) | Mafic (same as basalt but intrusive) | Slow cooling of mafic magma deep underground | Basalt's plutonic twin, forms lower oceanic crust, marketed as 'black granite' for countertops, dense and dark |
Diorite | Coarse-grained (phaneritic) | Intermediate (plagioclase + hornblende) | Slow cooling at intermediate depths | Salt-and-pepper appearance, Code of Hammurabi carved on diorite pillar, andesite's plutonic equivalent |
Scoria | Vesicular (porous, dark) | Mafic to intermediate | Gas-rich basaltic lava ejected from volcanic vent | Dark pumice-like rock but denser (sinks in water), cinder cones built from scoria, used as landscaping rock |
Tuff | Pyroclastic (consolidated ash) | Varies (depends on eruption) | Volcanic ash and fragments cemented together after eruption | Cappadocia's cave dwellings carved in tuff, Roman concrete used tuff, Moai of Easter Island carved from tuff |
Pegmatite | Very coarse-grained (>2.5 cm crystals) | Usually felsic (granitic) | Extremely slow cooling of water-rich magma residue | Source of giant crystals and rare minerals, lithium and beryllium mining, crystals can be meters long |
Dacite | Fine-grained, often porphyritic | Intermediate to felsic (63-69% SiO2) | Eruption of intermediate-silica magma at subduction zones | Mount St. Helens' 1980 eruption was dacite, forms lava domes, between andesite and rhyolite in composition |
Peridotite | Coarse-grained (phaneritic) | Ultramafic (olivine-rich, <45% SiO2) | Crystallization deep in upper mantle | Makes up Earth's upper mantle, source rock for diamonds (kimberlite is a type), rare at surface, weathers green |
Porphyry | Porphyritic (large crystals in fine matrix) | Varies (commonly intermediate) | Two-stage cooling — slow then fast | Imperial Porphyry prized by Roman emperors, born in purple (porphyrogenitos), Egyptian quarries, striking purple-red |
Ignimbrite | Welded pyroclastic (compacted) | Usually felsic (rhyolitic ash) | Pyroclastic flow deposits welded by extreme heat | Formed by catastrophic eruptions, covers vast areas, welded at 500-600°C, Valley of Ten Thousand Smokes in Alaska |
Free to explore · No signup needed
Related Datasets
More in Science
Periodic Table Elements
All 118 chemical elements of the periodic table with symbols, categories, discoverers, and what each element is known for.
Dinosaur Species
The most famous dinosaurs that ever roamed Earth — from the mighty T-Rex to the towering Brachiosaurus.
Planets of the Solar System
All 8 planets of our solar system with type, distance from the Sun, diameter, moon count, and orbital period in Earth years.
Gemstones & Precious Stones
Popular gemstones and precious stones with their physical properties, primary sources, symbolism, and market value.
Famous Paradoxes in Mathematics & Logic
Banach-Tarski, Monty Hall, the Birthday Problem, Russell's Paradox — which mathematical paradox most defies your intuition?
Types of Historical Clock & Timekeeping
Sundials, water clocks, atomic clocks — which timekeeping invention was the most transformative?