> Minerals
|
Obsidian
is not a mineral but volcanic glass formed as an extrusiv igneous rock. Obsidian is a mixture of amorphouse or cryptocrystalline grains of silica minerals formed as a result of quickly cooled lava. Petrograficaly belong the obsidian to the rhyolit-dacit family.
|
Synonyms: |
Bergmahogany, Black Lava Glass, Hyalopsite, Isophyre, Xaga |
Varieties: |
Fire Obsidian, Mahogany Obsidian, rainbow Obsidian, Sheen Obsidian, Snowflake Obsidian |
Classification: |
Igneous rock, volcanic glass, rhyolit-dacit family |
Tenacity: |
Brittle |
Fracture: |
Conchoidal |
Colour: |
Black, grey, green, reddisch, bluish, mahogany, golden, peacock |
Lustre: |
Vitreous |
Transparency: |
Translucent |
Application: |
Gemstone |
|