Obsidian Pyramid 01 - Black Sacred Geometry Stone Crystal Healing (2.7 Inches) Measures: Approx 2.7 inches (3.7 inches, diagonal) Weighs: Approx 8 ounces (226 grams) Stone Properties: Obsidian to transmute negative energies to positive; protecting the aura. Limited-Edition: Natural Obsidian is polished into your new crystal healing pyramid. This is a shiny black volcanic stone which may show the occasional white bubble inclusion. The Obsidian is polished into a 2.7 inch wide, 3.7 inch diagonal pyramid. When volcanic lava cools quickly, it forms shiny Black Obsidian healing crystals. Black Obsidian has cooled fast enough that no air bubbles or minerals have been included in the crystal. This pure black crystal is opaque with a glassy luster. Includes: 1 Obsidian Pyramid when purchased from I Dig Crystals.