The rhinoceros horn is considered as one of the 'Eight Precious' symbols. It was known to the Chinese for its power to detect poison which resulted in the creation of these specific food and drink vessels.
The quality of carving of this horn is exquisite and three-dimensional. Some very nice and close examples of such rhinoceros horns with landscapes and figures can be found on Thomas Fok, Connoisseurship of Rhinoceros Horn Carving in China, Hong Kong 1999. See particularly pl.162 which has similar landscape patterns and also the same rocks and trunks of pine trees powerfully modeled and rising over the rim into the cup.
Another rhinoceros horn libation cup illustrated in Bamboo, Wood, Ivory and Rhinoceros Horn Carvings - The Complete Collection of Treasures of the Palace Museum, Hong Kong 2002, pl.145 is very similar to the present one. The shape, colour and landscape patterns are very much alike.