What's That Rock?

Obsidian

Rock ⚠️ Handle with care

Natural volcanic glass formed when lava cools very quickly. It is usually black and breaks into very sharp edges.

Safety

Broken edges are extremely sharp.

How to identify Obsidian

  1. Glassy, smooth, no visible crystals
  2. Breaks with curved shell-like surfaces and razor-sharp edges
  3. Lighter than a similar-sized metal ore

Often confused with

Real or fake?

  • Man-made black glass can be hard to tell apart; look for bubbles or perfectly even shine
  • Obsidian often shows flow lines, tiny white 'snowflakes' or color sheens

Is Obsidian valuable?

Inexpensive.

Typical retail prices

Tumbled stone$1–3each
Rough$5–20per pound
Polished piece$5–60each

Typical retail ranges in US dollars, compiled from public dealer and marketplace listings in October 2026. Real prices vary widely with quality, size and origin. This is general information, not an appraisal.

What changes the price

  • Type: rainbow, sheen, snowflake, mahogany and mahogany-banded obsidian cost more than plain black
  • Size and polish: spheres, mirrors and blades are priced by size and finish
  • Origin: Mexican, Oregon and Iceland pieces are common; rare color varieties are scarce
  • Edges are razor sharp: handle broken pieces with care

Uses

  • Ancient stone tools and blades
  • Carvings, beads, jewelry

Care

Brittle and can chip. Handle broken pieces carefully, the edges cut.

Related stones

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Identifying a stone from a description or a photo is an estimate. Many stones look alike. Ask an expert or a gem lab before you buy, sell or rely on an identification.

Updated October 2026