Midnight Lace Obsidian Identification Guide
A practical field guide to identifying Midnight Lace Obsidian by its black glassy body, thin sheen-banding, and conchoidal fracture.
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What Midnight Lace Obsidian Looks Like
Midnight Lace Obsidian is a banded variety of volcanic glass (obsidian). Its body is deep black, but tilting it under a light reveals fine, lacy bands and swirls that flash a soft silver, gray, or bluish sheen. These delicate flow lines are the "lace."
- Color: Black overall, with thin gray/silver/blue sheen bands.
- Luster: Bright vitreous (glassy).
- Transparency: Opaque to translucent on thin edges.
- Habit/form: Massive, non-crystalline (amorphous glass); no crystal faces.
How the lace forms
The banding is frozen flow structure from viscous lava, sometimes with submicroscopic gas bubbles or crystallites aligned along flow planes, which scatter light to make the sheen.
Step-by-Step Field ID Checklist
- Confirm it is glass: Look for a bright, wet-looking vitreous luster and smooth, shell-like (conchoidal) fracture with razor edges.
- Check the body color: Solid black in normal light.
- Tilt under a light source: Rotate the specimen slowly. Genuine Midnight Lace shows thin, threadlike sheen bands that appear and vanish as the angle changes.
- Inspect for bubbles or crystallites: A loupe may show tiny spheres or needle-like crystallites along the bands.
- Test hardness and fracture (below).
Key Diagnostic Tests
- Mohs hardness: ~5–5.5. It will scratch glass marginally and is scratched by a steel file; a quartz point (7) scratches it.
- Streak: White to pale gray (glass has no true mineral streak; powder is light).
- Fracture: Conchoidal — smooth, curved, with sharp cutting edges. No cleavage.
- Density: ~2.35–2.6 g/cm3, noticeably light for a black "rock."
- Acid: No reaction to dilute HCl.
- Magnetism: Non-magnetic.
Common Look-Alikes and How to Tell Them Apart
- Rainbow / sheen obsidian: Same glass, but sheen is broad iridescent bands of color, not fine gray "lace." Midnight Lace has tighter, threadier banding.
- Black tourmaline (schorl): Forms striated prismatic crystals, hardness 7+, and shows no flow banding.
- Jet: Much lighter (density ~1.3), warm to the touch, brown streak, and burns with a coaly smell.
- Black glass slag / man-made glass: Often has rounded surfaces, mold marks, or trapped perfectly round bubbles; lacks natural flow lace.
- Black onyx/agate: Harder (7), waxy not glassy, and shows no conchoidal flow sheen.
Where It Is Found
Midnight Lace Obsidian comes from rhyolitic volcanic areas, notably the western United States (Oregon, Nevada, Arizona) and Mexico, wherever silica-rich lava cooled too fast to crystallize.
Frequently asked questions
How can you tell if Midnight Lace Obsidian is real?
Confirm it is volcanic glass: vitreous luster, conchoidal fracture with sharp edges, hardness about 5–5.5, and light weight. Real Midnight Lace shows fine gray/silver lacy sheen bands that shift as you tilt it under light, unlike molded man-made glass with round bubbles and mold seams.
What does Midnight Lace Obsidian look like?
It is a glossy black glass that reveals thin, lacy bands of silver, gray, or blue sheen when tilted toward a light. The body stays black; the delicate flow-banding is what distinguishes it.
Midnight Lace Obsidian vs rainbow obsidian?
Both are banded obsidian. Rainbow obsidian shows broad, colorful iridescent sheen bands, while Midnight Lace shows finer, threadlike gray-to-silver lace banding.
Is Midnight Lace Obsidian the same as black obsidian?
It is the same material (volcanic glass), but plain black obsidian is uniformly black with no internal structure, whereas Midnight Lace has visible lacy flow bands and a subtle sheen.