Quick Facts
Formation & Origin
Mahogany obsidian is volcanic glass colored by iron oxide (hematite and magnetite) inclusions that create warm mahogany-brown to reddish-brown swirled patterns against the black obsidian base. The iron oxides were present in the original lava but weren't fully dissolved - as the glass cooled rapidly, they remained as distinct inclusions creating the characteristic flowing patterns.
The swirled appearance records the last moments of lava flow before solidification. The iron-rich and iron-poor areas were being mixed by the flowing lava when it froze into glass. This means each piece of mahogany obsidian is a snapshot of volcanic dynamics captured in stone.
Like all obsidian, mahogany obsidian is geologically young. Obsidian devitrifies (converts from glass to crystal) over millions of years, so all obsidian is less than about 20 million years old. Most commercially available material is much younger.
Identification Guide
Mahogany obsidian is identified by its characteristic black and mahogany-brown swirled pattern, conchoidal fracture, and vitreous (glassy) luster. At hardness 5.5, it's softer than quartz.
Distinguish from tiger iron (metallic luster, much denser), banded jasper (opaque throughout, no glassy fracture), and dyed glass (too uniform). The conchoidal fracture with sharp edges is characteristic of all obsidian varieties.
Spotting Fakes
Mahogany obsidian is common and inexpensive enough that faking is rare. Manufactured glass in brown-and-black patterns does exist but lacks the natural flow patterns of genuine volcanic glass. Under magnification, genuine mahogany obsidian shows irregular, flowing boundaries between the dark and mahogany zones, while manufactured glass tends to have more regular patterns.
Cultural & Metaphysical Traditions
Presented as cultural traditions, not scientific evidence
Mahogany obsidian combines the protective grounding of black obsidian with the warm, strengthening energy associated with iron-bearing red-brown stones. Modern practitioners associate it with releasing inner limitations, building confidence, and finding strength during vulnerable moments. Its warm tones make it feel more approachable than pure black obsidian to many users.
Where It's Found
Quality material from volcanic regions
Commercial quantities
Some material available
Price Guide
Good to Know
Scratch test: At hardness 5.5, Mahogany Obsidian resists scratching from a knife but can be scratched by quartz. Best for pendants and earrings rather than rings.
Sources: Found in 3 notable locations worldwide, from United States to Japan.
Heft test: With a specific gravity of 2.40, Mahogany Obsidian feels lighter than most minerals. This lightness can help identify it.