Аннотация:Leucoxene grains contain inclusions of other minerals in small quantities: in addition to quartz, these are hydromuscovite-illite, kaolinite, florencite, xenotime, monazite, unusual metamict zircon with Y, U and HREE, siderite, pseudorutyle. New evidence has been obtained that the transformation of ilmenite into leucoxene occurs precisely by hydrothermal means: 1) enlargement of rutile crystals in the leucoxene grain itself: 2) finding secondary crystals of siderite, zircon, florencite, pseudorutyl, etc. inside leucoxene grains.