LIVE REPORT! The 49th Treasures of the Earth Show - Albuquerque, New Mexico - last updated 4 minutes ago. Click here to watch.
Donate now to keep alive!Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on Mindat
What is a mineral?The most common minerals on earthMineral PhotographyThe Elements and their MineralsGeological TimeMineral Evolution
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery


This page is currently not sponsored. Click here to sponsor this page.
black, bluish, mahogany, golden, peacock, etc. - the colors due largely to refraction by microscopic bubbles (and microscopic mineral inclusions such as magnetit in "Rainbow Obsidian").
Glassy, fresh igneous rocks with a high silica content and conchoidal fracture

Volcanic glass - a rock rather than a mineral, it is a mixture of cryptocrystalline grains of silica minerals in a glass-like suspension, a super-cooled liquid. Obsidian is formed in the latest stage of volcanic eruptions, the silicas left over after most of the other elements and water have been used up are ejected or flow out and rapidly chilled at surface temperatures.

Note on "Transparent/Translucent Obsidian":
A lot of gem-quality water-clear variously coloured 'obsidian' has been offered for sale on the internet (in particular on auction websites) with a variety of sources listed. The material offered for sale is in fact an artificial glass mass-produced in places such as Indonesia.

Visit for gemological information about Obsidian.

Hide all sections | Show all sections

Classification of ObsidianHide

Sub-divisions of ObsidianHide

Mineralogy of ObsidianHide

Essential minerals - these are minerals that are required within the classification of this rock:
GlassAn amorphous, homogeneous material with a random liquid-like structure generally formed due to rapid cooling.

Physical Properties of ObsidianHide

black, bluish, mahogany, golden, peacock, etc. - the colors due largely to refraction by microscopic bubbles (and microscopic mineral inclusions such as magnetit in "Rainbow Obsidian").

Synonyms of ObsidianHide

Other Language Names for ObsidianHide

Simplified Chinese:火山玻璃

Varieties of ObsidianHide

Fire ObsidianAn iridescent variety of obsidian. Its 'fire' is caused by thin layers of microcrystals of magnetite (which are approximately the thickness of a wavelength of light). The colour of Rainbow Obsidian occurs from a much thicker volume of the specimen (Nadin,...
Mahogany Obsidian
Rainbow ObsidianObsidian with multicolored iridescence caused by inclusions of magnetite nanoparticles (Nadin, 2007).
Sheen ObsidianA variety of obsidian exhibiting a golden sheen effect.
Snowflake ObsidianA rock - a natural volcanic glass containing white 'snowflake' crystal patterns of the mineral cristobalite, originated due to partial crystallisation of the glass.

Common AssociatesHide

Associated Minerals Based on Photo Data:
Cristobalite49 photos of Obsidian associated with Cristobalite on
Apache Tears27 photos of Obsidian associated with Apache Tears on
Fayalite14 photos of Obsidian associated with Fayalite on
Pyroxene Group5 photos of Obsidian associated with Pyroxene Group on
Quartz2 photos of Obsidian associated with Quartz on
Opal-C2 photos of Obsidian associated with Opal-C on
Spessartine1 photo of Obsidian associated with Spessartine on
Rose Quartz1 photo of Obsidian associated with Rose Quartz on
Jasper1 photo of Obsidian associated with Jasper on
Tiger's Eye1 photo of Obsidian associated with Tiger's Eye on

References for ObsidianHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Stevenson, R.J., Dingwell, D.B., Webb,S.L., and Bagdassarov, N.S. (1995) The equivalence of enthalpy and shear stress relaxation in rhyolitic obsidians and quantification of the liquid-glass transition in volcanic processes. Journal Volcan. Geotherm. Res.: 68: 297-306. (International Association for Obsidian Studies)

Internet Links for ObsidianHide URL:
Please feel free to link to this page.
Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2018, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: March 18, 2018 00:05:44 Page generated: March 17, 2018 19:33:22
Go to top of page