Isotopic composition of noble gases and other volatiles (CO₂, N₂) from minerals of corundum-bearing rocks with isotopically ultralight oxygen from Khitoostrov deposit have been investigated. The studies were conducted on Finesse mass-spectrometry system [1] using step heating in temperature range from 200ºС to 1400ºС. The following minerals were investigated: corundum, amphibole, garnet, staurolite. For the same samples, differential scanning calorimetry and thermogravimetry curves have been obtained. The first results of the studies show that the low-temperature (less than 400°C) release peaks of carbon dioxide and nitrogen probably represent a laboratory organic contamination. The middle-temperature release peaks (400-800ºC) are potentially consistent with decrepitation of fluid inclusions and diffusion of the gases from crystalline lattice of the minerals, and the high-temperature release peaks (900-1400ºC) possibly indicate the transformation of mineral structures such as amphibole and staurolite as a result of dehydration.