https://www.daotiancrystal.com/Optical-crystal-medallion-A-unique-souvenir.html Optical crystal medallion: A unique souvenir https://www.daotiancrystal.com/DT-premium-alternative-to-traditional-medals-with-3d-custom-engraving-to-award-t.html The optical crystal medallion is a unique souvenir made from high-quality optical crystal with a high degree of transparency and luster. The design and production process of this souvenir is very delicate, and every detail is carefully carved and polished, making it a very precious gift.