Green Swirl - 10in. Luminescent crystals embedded in the green tinted glass swirl of this gazing ball or garden globe, absorb light energy during the day and release it at night in form of a subtle green glow. Glow duration may last up to 3- 4 hours, gradually fading over that time. In addition to use outdoors, the Illuminarie Globe works equally well in an interior environment as long as it receives ample sunlight during the day.