• neptune@dmv.social
    link
    fedilink
    English
    arrow-up
    92
    ·
    8 months ago

    It’s the cooling of silica (really, any material) that makes it a glass, and even then, transparency in the visual wavelength is not automatically certain.

      • neptune@dmv.social
        link
        fedilink
        English
        arrow-up
        57
        ·
        8 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.