Rhyolite

Main Elements:

Si, Al, K, Na, O

Chemical Composition:

SiO₂ 69-77%, Al₂O₃ 12-17%, K₂O 3-5%, Na₂O 3-5%, FeO 1-3%, CaO 0.5-2%, MgO 0.1-1%

Density:

2.35 – 2.70 g/cm³

Compressive Strength:

50 – 200 MPa

Melting Point:

700 – 900°C

Formation:

Forms from viscous, silica-rich lava flows that cool quickly on the Earth's surface. Often associated with explosive volcanic eruptions.

Composition:

Composed mainly of quartz and feldspar, similar to granite but with finer grain size due to rapid cooling.

Types:

• Flow-banded Rhyolite
• Porphyritic Rhyolite
• Obsidian (glassy rhyolite)

Etymology:

Derived from the Greek word "rhyax" meaning "stream of lava", combined with "-lite" meaning stone.

Uses:

• Decorative stone
• Ancient arrowheads
• Jewelry
• Building material

Distribution:

Found in volcanic regions worldwide, especially Yellowstone, New Zealand, and Germany

Historical Use:

Used by ancient peoples for tools and weapons. Yellowstone's geysers are powered by rhyolite magma.

Symbolism:

Represents volcanic activity and Earth's fiery nature

What is rhyolite?

Rhyolite is a fine-grained igneous rock that forms from viscous lava flows. It is the volcanic equivalent of granite.

Where is rhyolite found?

Rhyolite is found in volcanic regions worldwide, including Yellowstone National Park, New Zealand, and Germany.

How does rhyolite form?

Rhyolite forms when silica-rich lava cools rapidly on the Earth's surface, preventing large crystals from forming.