The ter'angreal is a deep blue carving of seemingly random curves similar to roots. It feels like stone, but does not actually look like it was carved. It warms slightly to the touch and held a "resonance" to saidar.
The exact use of the carving is unknown, but it is confirmed that it is for growing something if the correct song is sung to it. In all likelihood, this ter'angreal is the Talisman of Growing for creating Waygates.
"A stone carving the size of her [Aviendha] hand, all deep blue curves – it felt like stone, at least, though somehow it did not really look carved – was for growing something. Not plants. It made her think of holes, only they were not exactly holes. And she did not believe anyone had to channel to make it work. Only sing the right song!"