Embodiments of the disclosure generally relate to a support cylinder used in a thermal process chamber. In one embodiment, the support cylinder comprises a ring body having an inner peripheral surface and an outer peripheral surface, wherein the ring body comprises an opaque quartz glass material and wherein the ring body is coated with an optical transparent layer. The optical transparent layer has a coefficient of thermal expansion that is substantially matched or similar to the opaque quartz glass material to reduce thermal expansion mismatch that may cause thermal stress under high thermal loads. In one example, the opaque quartz glass material is synthetic black quartz and the optical transparent layer comprises a clear fused quartz material.