• teft
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    749 months ago

    Case in point, obsidian.

    • @[email protected]
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      609 months ago

      Good example. Obsidian is apparently 70% silica. Iron is apparently what makes it black in color. If it’s thin enough, it is translucent.

      If you cool pure silica slowly enough, with impurities to cause seeding, you will get tons of crystals, not a single glass, that won’t be transparent.