gemstone

Black onyx or black obsidian bead bracelet

Likely black chalcedony (microcrystalline quartz, SiO₂); possibly volcanic glass (obsidian, SiO₂)

AI-generated identification · may be incorrect

Small polished, spherical black beads with vitreous to waxy luster; likely opaque, hardness about 6.5–7 for onyx or 5–5.5 for obsidian, with no visible cleavage. The image cannot reliably distinguish the materials; uniform black color and polish are typical of both.

Identified September 1, 2026More gemstone →

Explore Black onyx or black obsidian bead bracelet in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Black onyx or black obsidian bead bracelet
Scientific name: Likely black chalcedony (microcrystalline quartz, SiO₂); possibly volcanic glass (obsidian, SiO₂)
Category: gemstone
Identified: September 1, 2026
Method: Standard

AI Estimated Value

$5–$30 for a common bracelet; approximately $30–$100 if confirmed as high-quality natural onyx or unusual obsidian.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Black onyx forms when silica-rich groundwater deposits chalcedony in cavities or fractures; obsidian forms when silica-rich lava cools rapidly. These materials are geologically young to ancient depending on the deposit.

Uses & applications

Used for jewelry, beads, ornamental objects, and carvings. Common commercial material has modest value.

Geological facts

“Black onyx” jewelry is often dyed chalcedony, while solid black obsidian is natural volcanic glass; beads may also be dyed agate or manufactured glass.

Field identification & locations

Onyx feels cool and is slightly harder, commonly showing subtle banding under strong light; obsidian has glassy conchoidal fracture. A refractive-index, hardness, or laboratory test is needed for confirmation. Common sources include Brazil, India, Mexico, Turkey, and the United States.