Introduction to Black Beach: Macau Black Beach, known as Dahuan in ancient times, is a natural beach. The black sand is characterized by dark, smooth sand, hence the name of the beach. It is said that the fine black sand is caused by the black secondary mineral glauconite formed in the specific environment of the ocean. Affected by ocean currents, glauconite is carried close to the coast and then carried to the beach by wind and waves, turning the original white sand beach into a charming and mysterious black sand beach.