Obsidian PURIFICATION | MANIFESTATION | TRANSFORMATION Obsidian, a volcanic glass, is a protective stone that shields against negativity. It brings a clear mind, allowing for easier manifestation. A great tool for those looking to make changes in their life. This listing is for ONE (1) Obsidian Mini Mushroom. Approximate weight: 0.15-0.3 oz Approximate length: 0.8-0.9" Please note, stones are natural and WILL vary in precise size, shape, color, pattern, etc., and may not exactly match photo.