There are two pendant pearls which are among the collections of the United States National Museum. These pearls were given to President Martin Van Buren in 1840 from the Imam of Muscat, along with a necklace consisting of 148 pearls.

Each of the single pendant pearls are approximately 30 grains and the necklace is said to be about 700 grains. The diameter is believed to be around 5.0 to 6.0 mm. The pearls were most likely from the Persian Gulf which makes them oriental pearls. Because these pearls were given to a President, it is very likely that they were of the best quality pearls. Therefore, these pearls are said to be spherical and white with near perfect surface quality.