Violet Obsidian Identification Guide
How to identify Violet Obsidian, a purple-tinted volcanic glass, and distinguish natural pieces from dyed or man-made glass.
Read the full Violet Obsidian encyclopedia entry →
What Violet Obsidian Looks Like
Violet Obsidian is a volcanic glass (obsidian) with a purple to lilac tint, usually subtle and seen best when held to light.
- Color: smoky violet, lavender or purple-grey, often darkening to near-black; color may be uneven or cloudy.
- Luster: bright vitreous (glassy).
- Transparency: translucent on thin edges, opaque in thick pieces.
- Form: massive, amorphous glass, no crystals; broken pieces show smooth, curved (conchoidal) fracture with sharp edges.
Step-by-Step Field Checklist
- Backlight it. Hold the stone to a strong light; natural violet obsidian shows a soft, often patchy purple glow.
- Check the fracture. Look for conchoidal (shell-like) curved breaks and razor-sharp edges, classic glass behavior.
- Test hardness. It scratches glass marginally (Mohs ~5-5.5) and is brittle.
- Feel the temperature. Glass warms slowly and feels cool initially.
- Look for flow texture. Faint banding or swirl from lava flow supports a natural origin.
Key Diagnostic Tests
- Mohs hardness: ~5-5.5; brittle.
- Streak: white.
- Cleavage/Fracture: none; pronounced conchoidal fracture.
- Density: ~2.35-2.6 g/cm3, light.
- Acid/Magnetism: no reaction; not magnetic.
Common Look-Alikes
- Manufactured/slag glass: the most common confusion. Man-made glass often shows abundant rounded gas bubbles, perfectly even color, and sometimes mold seams. Obsidian bubbles, if present, are sparse and elongated; many natural pieces show flow lines or tiny crystallites.
- Dyed/coated obsidian: beware uniform, vivid purple coatings; check for color concentrated in surface scratches.
- Amethyst/fluorite: crystalline (show crystal faces and, for fluorite, cleavage); amethyst is harder (7).
- Purple chalcedony: harder (7), waxier luster, no conchoidal glass sheen.
Where It Is Found
Obsidian forms where silica-rich (rhyolitic) lava cools too fast to crystallize, around young volcanoes: the western USA (Oregon, California, Arizona, New Mexico), Mexico, Iceland, Armenia and Japan. Violet hues are uncommon, so examine carefully, since much "violet obsidian" on the market is colored glass.
Frequently asked questions
Is Violet Obsidian natural?
True violet obsidian exists but is uncommon; much purple material sold is dyed obsidian or man-made glass. Check for sparse elongated bubbles, flow lines, and color that is not concentrated in surface scratches.
How can you tell real Violet Obsidian from glass?
Manufactured glass usually has many round bubbles and perfectly even color, sometimes mold seams. Natural obsidian shows conchoidal fracture, flow texture, and only sparse, elongated bubbles.
What does Violet Obsidian look like?
It is a glassy, translucent-to-opaque volcanic glass with a smoky purple or lavender tint, bright vitreous luster, and curved shell-like fractures with sharp edges.
How hard is Violet Obsidian?
About 5 to 5.5 on the Mohs scale, so it is brittle and only marginally scratches window glass; it is softer than quartz.
Violet Obsidian identified by the community
Recent Violet Obsidian specimens identified with Rock Identifier.
