Pale yellow fibres of studtite on matrix with bright yellow crusts made up of a mixture of phosphuranylite and saleeite. Studtite is a very unusual uranium species because it is the only known mineral that contains the peroxide radical (you only encounter this radical in the form of hydrogen peroxide antiseptic). Peroxide is produced in nature by hydrolysis of water caused by strong radiation from rich uranium ores. In these rare cases Studtite can form.
