Percylite – Amelia Mine, Santa Rosalía (El Boleó), Boleó District, Mun. de Mulegé, Baja California Sur, Mexico
 Former collection of Émile Deyrolle (1838–1917)
 Deep blue cubic percylite as a single crystal from the type locality.
 Percylite = mixture of boleite and pseudoboleite
 Particularly noteworthy is the crystal's exceptional, historical presentation. The crystal, complete with a crystal drawing, is packaged in an old test tube with a cork stopper.
 A curiosity for every mineral collection!
 Émile Deyrolle (1838-1917) was a French naturalist and natural history dealer in Paris. The business originally belonged to his grandfather, the naturalist Jean-Baptiste Deyrolle, who opened his shop at 23 Rue de la Monnaie in 1831. Émile's father, Achille Deyrolle, managed the business for many years. Émile took over in 1866. The address from 1881 (and today) was (and remains) 46 Rue du Bac, the former home of Jacques Samuel Bernhart. Deyrolle specialized in natural history publications and specimens, minerals, rocks, fossils, botanical specimens, shells, specimens, microscopic specimens, and microscopes.