Obsidian

Q: What is Obsidian?

Obsidian is a naturally occurring volcanic glass formed from rapidly cooling silica-rich rhyolitic lava, typically opaque to translucent black, though also produced in mahogany brown, rainbow iridescent (rainbow obsidian), translucent gray (Apache tears), and spotted snowflake varieties. It has been

Q: What is the hardness of Obsidian?

Obsidian has a Mohs hardness of 5.0 to 5.5, making it moderate for use in jewelry.

Q: How much does Obsidian cost?

Obsidian falls into the Budget (< $50/ct) price range. Prices vary based on color, clarity, cut, and origin.

Q: What is the crystal system of Obsidian?

Obsidian belongs to the Amorphous crystal system.

Add one script tag to your page:

<div data-gemfyi="entity" data-slug="obsidian"></div>
<script src="https://cdn.jsdelivr.net/npm/gemfyi-embed@1/dist/embed.min.js" defer></script>

Embed as an iframe:

<iframe src="https://gemfyi.com/iframe/entity/obsidian/?style=modern&theme=light" width="420" height="400" frameborder="0" loading="lazy" style="border:0;border-radius:10px;max-width:100%"></iframe>

Paste the URL in WordPress, Medium, or Ghost:

https://gemfyi.com/gems/obsidian/

Shields.io-compatible SVG badge:

![Obsidian](https://gemfyi.com/badge/entity/obsidian.svg)

Web Component:

<gemfyi-entity slug="obsidian"></gemfyi-entity>
<script src="https://cdn.jsdelivr.net/npm/gemfyi-embed@1/dist/embed.min.js" defer></script>

A naturally occurring volcanic glass formed when silica-rich rhyolitic lava cools too quickly to crystallize, obsidian is typically opaque black but also occurs in mahogany brown, iridescent rainbow, translucent gray Apache tears, and spotted snowflake forms. It has been worked since the Paleolithic into extremely sharp blades, tools, and mirrors, and was traded widely across Mesoamerica, the Mediterranean, and the Pacific. Amorphous and without crystal structure, it measures 5.0 to 5.5 on the Mohs scale. Today this budget-tier semi-precious material is cut into cabochons, carvings, and spheres valued for their variety of patterns.

Physical & Optical Properties

Category Semi-Precious Gems

Mohs Hardness 5.0 – 5.5

Specific Gravity 2.35 – 2.6

Refractive Index 1.45 – 1.55

Crystal System Amorphous

Luster Vitreous

Cleavage None

Fracture Conchoidal

Color black

Dispersion 0.01

Pleochroism Absent

Mohs Hardness

Mohs Hardness: 5.0 – 5.5

1 Soft10 Hard

Crystal System

Value & Market

Price Tier Budget (< $50/ct)

Where to Buy Obsidian

Blue Nile Fine jewelry retailer

James Allen Gemstone jewelry

Brilliant Earth Ethically sourced gems

Amazon Wide selection

Links may earn a commission at no extra cost to you.

About Obsidian

Obsidian is a naturally occurring volcanic glass formed from rapidly cooling silica-rich rhyolitic lava, typically opaque to translucent black, though also produced in mahogany brown, rainbow iridescent (rainbow obsidian), translucent gray (Apache tears), and spotted snowflake varieties. It has been used since the Paleolithic era for knapping extremely sharp cutting tools, blades, and mirrors, and was traded extensively in Mesoamerica, the Mediterranean, and across the Pacific by ancient cultures. Today obsidian is fashioned into cabochons, carvings, and spheres prized for the variety of patterns and colors.