Obsidian

Main Elements:

Si, O, Al, Na, K

Chemical Composition:

SiO₂ 70-75%, Al₂O₃ 12-15%, Na₂O 3-5%, K₂O 3-5%, FeO 1-3%, MgO 0.5-2%

Density:

2.35 – 2.60 g/cm³

Compressive Strength:

Variable

Melting Point:

700 – 1000°C

Formation:

Forms when lava cools so quickly that crystals cannot form, resulting in a glassy texture. Requires high silica content and rapid cooling.

Composition:

Composed of volcanic glass with no crystalline structure. Similar composition to rhyolite but without crystal formation.

Types:

• Black Obsidian
• Mahogany Obsidian
• Snowflake Obsidian
• Rainbow Obsidian

Etymology:

Named after Obsius, a Roman who supposedly discovered it in Ethiopia, though the name may have earlier origins.

Uses:

• Ancient tools and weapons
• Modern surgical scalpels
• Jewelry
• Decorative items

Distribution:

Found in Iceland, Italy, Mexico, United States (Oregon, California), and other volcanic regions

Historical Use:

Used by ancient peoples worldwide for cutting tools and weapons. Obsidian blades can be sharper than steel.

Symbolism:

Represents protection, clarity, and sharp insight

Is obsidian sharp?

Yes, obsidian can be extremely sharp when fractured. Obsidian blades can be sharper than steel scalpels and were used by ancient surgeons.

Where is obsidian found?

Obsidian is found in volcanic regions worldwide, including Iceland, Italy, Mexico, and the western United States.