Basalt fibres were used as reinforcement of low-cost composites with ceramic matrix made by pyrolysis of their precursors, i.e., composites with various polysiloxane polymeric matrices. Due to favourable properties of both basalt fibre and ceramic matrix the composites reveal good chemical stability, thermal resistance and advantageous mechanical properties. They were assessed by evaluation of the fibre/matrix interface bonding and measurement of decisive elastic properties at elevated temperatures. The results confirm very good endurance to long-term oxidation in air even at 600 – 700°C. The measured temperature dependences of the Young’s modulus and shear modulus reveal sensitivity of the system to maximum heat treatment temperature experienced during manufacture. Microphotographs show various levels of fiber/matrix bonding in dependence of the polymer precursor type. Performance of the composites can thus be controlled by proper choice of the precursor.