The first experimental data on the heat capacities, enthalpies of formation from the oxides and elements of a natural elbaite: (Na0.48Ca0.44K0.02) (Li1.45Mn0.05Fe0.033+Mg0.09)Al7.01Si6.00B3.05(OH)(2.57)F0.44O27.18 (Malkhan pegmatite field, east Siberia, Russia) have been obtained. The heat capacities of elbaite were measured by DSC method from T = 270 to 540 K. High-temperature enthalpy increments were determined on the Tian-Calvet microcallorimeter at interval of 569-1023 K using the drop method. A value of Cdegrees(p,m) (298.15 K) = 757.3 JK(-1) mol(-1) was obtained and the resultant Cdegrees(p,m)(T) equation in the interval T = 298.15-1023 K was calculated: Cdegrees(p,m) = 919.7 + 366.2 x 10(-3)T - 241.4 x 105T(-2) (K-1 mol(-1)) (+/-1.4%). The standard molar enthalpy of formation from the elements was determined by high-temperature solution calorimetry in molten lead borate at T = 973 K on the Tian-Calvet microcalorimeter. The value of Delta(f)Hdegrees(m) (298.15 K) of elbaite was found to be -15129 +/- 19 kJ mol(-1). The value of Delta(f)Gdegrees(m) (298.15K) was calculated as -14213 kJ mol(-1). M (C) 2004 Elsevier B.V. All rights reserved.