Cave Amber (Chinese: Rong Dong Mi) is a highly rare and collectible variety of Burmese amber. It is famous for its unique visual effect, where translucent amber and opaque root amber interweave, resembling the dramatic landscapes of a limestone karst cave. Key Features & Formation Visual Contrast: It blends clear amber with opaque calcite-rich root amber in surreal, swirling patterns. Geological Origin: Formed over 100 million years ago when ancient tree resin mixed with calcium carbonate minerals. Extreme Rarity: It accounts for less than 1% of all Burmese amber production, making it highly valuable to collectors. Period: Cretaceous (100 million years old) Location: Hukawng Valley, Myanmar Size: Amber 26.2*14.5*5.8 mm