Ā Fire obsidian stands out as an extraordinary and scarce type of iridescent obsidian, exclusively located in southeast Oregon. Its distinctiveness lies in the vibrant colors and intricate patterns, attributed to the presence of thin magnetite layers within the glass. Displaying a spectrum that often encompasses red, orange, yellow, green, and blue hues, fire obsidian showcases patterns ranging from concentric circles to bands and various geometric shapes.
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| Fire Obsidian |
The genesis of fire obsidian is linked to the rapid cooling of lava, preventing crystal formation and resulting in a highly reflective, glassy material. The enchanting iridescent colors and patterns emerge from the interaction of light with the magnetite layers embedded within the obsidian.
Where to Find Fire Obsidian
This exceptional obsidian variation can only be found in the Steens Mountain Wilderness in southeast Oregon, where it originated approximately 4-5 million years ago during the eruption of a rhyolite dome. The collapse of the dome left behind dikes and obsidian flows, with fire obsidian concentrated in these narrow dikes, typically a few centimeters thick.
Key Facts About Fire Obsidian
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| Natural Fire Obsidian from Oregon |
- Name and Appearance: The name "fire obsidian" derives from the stone's appearance, resembling dancing and flickering flames. It is commonly referred to as "iridescent obsidian."
- Magnetite Layers: The magnetite layers, crucial for creating the iridescence, are incredibly thin, measuring only a few micronsāapproximately four times thinner than a human hair.
- Rarity and Value: Fire obsidian is a relatively rare gemstone, making it a sought-after possession due to its scarcity and captivating beauty. Its exclusivity contributes to its higher market value.
Properties of Fire Obsidian
- Chemical Composition - SiO2 (70-75%), FeO (10-14%), MgO (3-5%), Na2O (1-2%), K2O (0.5-1%)
- HardnessĀ -Ā 5-6 on the Mohs scale
- Specific GravityĀ -Ā 2.5-2.6
- FractureĀ -Ā Conchoidal
- LusterĀ -Ā Vitreous
- ColorĀ -Ā Varied, often including shades of red, orange, yellow, green, and blue
This gemstone, with its unique geological origin and distinctive properties, has become a highly coveted item for collectors and jewelry artisans. Additionally, fire obsidian holds cultural significance in certain traditional ceremonies, further enhancing its allure and value.