Jewel of the Dragon's Neck

The is a strange metal sphere with an exposed, yellow, glowing core. The jewel was found by Kanna in the basin of a shallow stream, surrounded by large bones, possibly belonging to a dragon. It signifies the element and is represented on Kaguya's seal by the color yellow.

Verse
The Jewel was cast into Lake Yamanaka with the verse:

English= Oh arrow of mine with power pure and immense to slay the dragon, do your good deed fast and swift; grasp the crystal in its neck. Nihongo= わが弓の力は龍あらば、ふと射殺して、首の玉はとりてむ Rōmaji= Waga yumi no chikara wa ryū araba, futo ikoroshite, kubi no tama wa toriten

Trivia

 * The Jewel of the Dragon's Neck is based on the one in.