Judging quality
Fine obsidian is free of gas bubbles and takes a flawless mirror polish. Rainbow obsidian must be cut at the correct angle to reveal its sheen — badly oriented cuts show nothing.
Volcanic glass
Obsidian
Not a mineral at all but volcanic glass, cooled too quickly for crystals to form. Varieties include snowflake, mahogany, sheen, rainbow and the translucent Apache tear.
Care
Softer than quartz and will scratch. Store separately and clean with a soft cloth.
History & lore
Obsidian blades from Mesoamerica and Anatolia are among the sharpest edges ever produced by hand, and obsidian mirrors were used for divination in Aztec practice.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Obsidian
- What is Obsidian?
- Not a mineral at all but volcanic glass, cooled too quickly for crystals to form. Varieties include snowflake, mahogany, sheen, rainbow and the translucent Apache tear.
- How hard is Obsidian and what is it made of?
- Obsidian is a Volcanic glass-family mineral with the composition SiO2 rich glass. It crystallizes in the amorphous system and rates 5-5.5 on the Mohs hardness scale. It occurs in black, mahogany, rainbow.
- Where does Obsidian come from?
- Notable localities for Obsidian include Mexico, USA (Oregon, California), Iceland, Armenia.
- How do you tell good Obsidian from filler?
- Fine obsidian is free of gas bubbles and takes a flawless mirror polish. Rainbow obsidian must be cut at the correct angle to reveal its sheen — badly oriented cuts show nothing.
- How do you care for Obsidian?
- Softer than quartz and will scratch. Store separately and clean with a soft cloth.
See it in person
Photographs only go so far
Both rooms are open six days a week, and there is always someone happy to pull pieces out of the case so you can compare them under the light.