Purple Obsidian Identification Guide
Identify purple obsidian by its glassy conchoidal fracture and hardness, and learn to distinguish it from amethyst and manmade glass.
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What Purple Obsidian Looks Like
Purple Obsidian is a volcanic glass with a violet to lavender tint, produced by trace inclusions and light scattering within the glass. It has a bright vitreous (glassy) luster, ranges from translucent to nearly opaque, and breaks with a smooth conchoidal fracture. Being glass, it has no crystal structure and no cleavage.
Genuine purple obsidian is uncommon in nature; a significant amount of "purple obsidian" on the market is actually manmade glass, so verification matters.
Step-by-Step Field ID Checklist
- Luster: Confirm a glassy, reflective surface.
- Fracture: Look for smooth, curved conchoidal breaks with sharp edges.
- Color: Hold to light to see the purple/lavender hue throughout the body.
- Hardness test: It scratches glass only weakly (Mohs ~5–5.5) and is softer than quartz.
- Bubble check: Natural obsidian may show stretched flow bubbles; perfectly round bubbles indicate manufactured glass.
Key Diagnostic Tests
- Mohs hardness: 5–5.5 (softer than amethyst at 7).
- Streak: white.
- Cleavage: none; conchoidal fracture.
- Structure: amorphous glass — no crystal faces.
- Inclusions/bubbles: spherical bubbles and overly even color point to slag/manmade glass.
Common Look-Alikes and How to Tell Them Apart
- Amethyst: crystalline quartz with crystal faces, harder (Mohs 7), and grows in geodes; purple obsidian is glassy, softer, and amorphous.
- Purple manmade/slag glass: shows perfectly spherical bubbles and uniform color; natural obsidian shows flow banding.
- Charoite / sugilite: opaque, fibrous or massive purple minerals, harder and lacking the glassy conchoidal fracture.
- Fluorite: softer (4) with cubic cleavage and transparency, unlike glassy obsidian.
The diagnostic package is glassy luster + conchoidal fracture + hardness 5–5.5 + amorphous (no crystals), followed by checking authenticity against manmade glass.
Where It Is Found
Natural purple-tinted obsidian is rare and tied to specific silica-rich volcanic flows; limited material is reported from areas such as Mexico and Armenia. Given its scarcity, treat most "purple obsidian" with care and verify it is volcanic glass rather than manufactured glass.
Frequently asked questions
Is purple obsidian real?
Natural purple obsidian exists but is rare; much material sold as purple obsidian is manmade glass. Verify by checking for a hardness of 5–5.5, conchoidal fracture, and absence of perfectly round bubbles.
What is the difference between purple obsidian and amethyst?
Amethyst is crystalline quartz with crystal faces and a hardness of 7, while purple obsidian is amorphous volcanic glass that is softer (5–5.5) with a glassy conchoidal fracture and no crystals.
How can you tell purple obsidian from manmade glass?
Natural obsidian shows flow banding and stretched bubbles, while manmade glass typically has perfectly spherical bubbles and overly uniform color.
What does purple obsidian look like?
It is a glassy, violet-to-lavender stone, translucent to opaque, with a bright vitreous luster and smooth curved fracture surfaces.