Ceramic glasses, e.g., Corning's 9600® or Schott's Zerodur® and Russia's Astrositall® have a lower expansion coefficient than Pyrex®. The lower expansion coefficient of expansion provides a more stable surface and leads to less distortion in temperature fluctuations. Ceramic glass is a internal blend of a crystalline structure and a normal glass structure. The crystalline structure off sets any expansion tendency of the glass in a certain temperature range. The material is first made as a glass then it is held at a given temperature that permits the crystalline structure to develop within the material. At a given point in the growth of the crystalline structure the temperature is changed to terminate the formation. This crystalline/glass structure results in nearly zero expansion or contraction over a wide temperature range.