Clearceram-Z and the improved version Clearceram-Z-HS, Ohara's newest transparent, ultra-low thermal expansion glass-ceramic offers such outstanding properties as high thermal resistance, hardness, mechanical strength, resistance to chemicals, and machine-ability. These properties have been achieved by carefully controlling raw materials, crystal size, and crystal volume. Applications include precision optics, astronomical telescopes, substrates, precision gauges and fixtures, surface flats, and precision machinery components.