how strong is obsidian

Obsidian is very hard but also surprisingly brittle: it resists scratching and compression well, yet it chips and shatters much more easily than many common engineering materials.

What obsidian actually is

• Obsidian is a naturally occurring volcanic glass formed when lava cools so quickly that crystals do not have time to grow.

• Because it is glass, its internal structure is disordered rather than the regular crystal lattice you see in minerals like quartz or diamond.

Hardness vs toughness

• In geology, “hardness” usually refers to scratch resistance, while “toughness” is resistance to cracking or breaking.

• Obsidian is quite hard in scratch terms, comparable to or a bit below quartz on the Mohs scale, but its toughness is low, which is why it fractures so sharply.

How strong is obsidian in practice?

• Edges of obsidian can be flaked to produce blades far sharper than most steel scalpels, which shows how well it can maintain a very fine edge.

• At the same time, those razor edges and the glassy structure mean an obsidian tool or weapon can break or chip if subjected to side impacts or bending forces.

Comparison to metals and crystals

• Metals like steel are usually less hard (more easily scratched) than obsidian but much tougher, so they bend or deform instead of shattering.

• Super-hard crystals like diamond are both harder and, in many configurations, mechanically more robust than obsidian, especially under controlled loading.

When obsidian is “strong enough”

• Obsidian is strong for cutting, piercing, and decorative uses where compressive loads dominate and impacts are controlled.

• It is not strong for structural applications (beams, armor, tools that take heavy hits), where its tendency to crack suddenly makes it unreliable compared to metals or tough ceramics.