The Balhae gold earrings were uncovered from Tomb No. 13 in the second district of ancient tombs at Gungsim along the Cheongchodeok ridge to the northeast of Hoeryeong city, North Hamgyeong Province. The "Taehwan style" (太環式) earrings are made of a thick, hollow ring interlocked with a thinner ring. The diameter of the thick ring and the bead below it is respectively 1.1 and 0.7 centimeters, while each earring's entire length is 4.3 centimeters, including the 0.6-centimeter triangle-shaped pendulum at the bottom.
Earrings from the ancient Korean kingdom of Balhae have so far been excavated from multiple sites in China such as the Liudingshan tombs in Dunhua County, the Dongqing burial grounds in Antu County, and Hailin County as well as in Korea's North Hamgyeong Province such as the Changdeok tombs in Hwadae County or Bugeo-ri of Cheongjin City. The featured earrings discovered at Changdeok Tomb No. 3 in Gungsim are very similar in form to the Taehwan style earrings from the kingdom of Koguryo. A thin, pure gold panel is rolled into a wide cylindrical shape, which is then interlocked with a narrower gilt bronze ring that has pure gold pendants dangling below it.
These gold and gilt bronze earrings show how sophisticated Balhae's goldsmith techniques were and are invaluable for demonstrating the fact that Balhae inherited Koguryo's culture.
Reference: Balhae Sites in Hoeryeong (Northeast Asian History Foundation, 2015)