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Volcanic materials

Short answer

Volcanic materials are gases (mainly water vapour, CO₂, SO₂), liquid lava (basaltic or rhyolitic), and solid pyroclasts. Pyroclasts include ash (<2 mm), lapilli (2–64 mm), bombs and blocks (>64 mm), pumice, scoria, tuff and volcanic breccia.

What are the different volcanic materials?

Volcanic materials ejected through the vent are of three kinds.

  1. Gases and vapours: water vapour (most), CO2_2, SO2_2, H2_2S, HCl, nitrogen.
  2. Liquid: lava (molten rock at the surface). Basic (basaltic) lava is runny; acid (rhyolitic) lava is thick.
  3. Solids (pyroclasts):
    • Volcanic dust and ash: less than 2 mm
    • Lapilli: 2 to 64 mm
    • Volcanic bombs and blocks: greater than 64 mm
    • Pumice, scoria, tuff, and volcanic breccia

✓ Answer checked by Claude Opus 5.5 (high effort)

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