Obsidian ball versus press
Obsidian is a massive dark volcanic glass. Obsidian is formed by the rapid cooling of acidic lava at the surface (lava) or by the rapid cooling of magma in near-surface conditions (dikes, rods or other cutting magma bodies).
Obsidian is a massive dark volcanic glass. Obsidian is formed by the rapid cooling of acidic lava at the surface (lava) or by the rapid cooling of magma in near-surface conditions (dikes, rods or other cutting magma bodies).